Looking at some of your other options:
Nassau is all boat diving - 2 dives are $100/120. Most of the beachfront resorts are pricier also. There's a couple of B&B's that are cheaper that are not in town. Some of the older hotels are not in the best areas and won't have kitchens. I have seen some decent deals at the British Colonial Hilton surprisingly - it's downtown. It's also a major cruise port and other areas are sort of marginal. Nice beaches though, beautiful white sand.
Stuart Cove's is the premier operator there. Except for Bahama Divers, they've pretty much under priced everyone else into closing. They bundle diving/hotel etc. in package deals on their website. They're also 45mins. south of town with a free shuttle.
Punta Cana is where people go to play golf. Diving there is secondary at best. Also all boat diving IIRC. We looked at it once and never again.
I have read here that a lot of Jamaica is seriously over fished.
All the better diving in San Juan is elsewhere, either south or west sides. Easily driveable in a morning. I've been there once. There aren't a lot of dive ops in San Juan since there's no business. About the only shore dive there is a shallow one off a park - a training site. I've read it's often murky.
I think your idea of shore diving to save is a good one but it might be best on Curacao for you.
Reasons are that Bonaire entries are over ironshore and coral rubble so difficult while balancing gear and helping your buddy. It's slick, hard and frequently in the surf line so hard to see. I really don't know anyone who never got cut up, scratched up or sprained something there. Unless they only dove from the resort docks or boats.
A Bonaire advantage is the reef starts fairly close offshore - sometimes within 40' or so. No dive sites on Bonaire outside of the resorts in town have any sort of facilities or amenities - bring everything you need and nothing else as there's some theft there also - while you're diving your vehicle may be gone thru. At the southern dive sites, you'll see other divers at many of the nearby sites, you can see 3-4 in either direction as it's flat scrubland. North it's more hilly. Several times in the afternoon we've been the only ones at a site.
Curacao has almost all sandy beach entries as dive sites. Almost all have an on-site dive operator for tanks/rentals etc. Most have some food option also - a couple have nice beachfront restaurants. The reef there starts farther out, often a short 5min. surface swim to the marker. At some of the western sites, the beach breaks the ironshore cliffs so good nav. skills are optimal. Curacao also has the Dive Bus. They do escorted shore diving but it's priced accordingly - 2/$100. They will pick you up, take you to the better sites and help you get oriented. Might be worth it once or twice. You will have to drive farther between shore dives on Curacao also, most are a 5-10min. drive to the water from the main road that bisects the island. Car rentals seem to run about $3-500. Most roads to the dive sites are paved or good dirt roads so you don't need a truck/jeep.
Either is very similar diving, I'd give the edge to Curacao for more interesting dives in general. A lot of Bonaire starts to look very similar later in the week. There's also some shallow wrecks on Curacao, either the plane wreck or the Tugboat - one of the signature Curacao dives. It's at 15' on the bottom, the nearby pier is under 40' and both are good dives.
The Hooker wreck on Bonaire is outside your skill set unless done with a DM. There's also a couple of shallow wrecks off Bonaire but they're old pleasure craft so not much to see. There's nothing on Bonaire like some of the verticality you can get off Curacao. Not quite deep walls but close.
If you really want to blow the budget, there's a Dolphin Dive on Curacao also. With Ocean Encounters main shop at the Sea Aquarium. $200pp...
Entry pictures/site descriptions for many sites on all three islands:
http://www.shorediving.com/Earth/ABC/index.htm
I've never been to Aruba. We bypassed it for both Bonaire and Curacao. If you can get to Aruba by late afternoon, there's an 8PM flight from there to either Bonaire or Curacao. Check Insel Air, Dutch Antilles Express or Tiara Air's websites for details. Coming back unless you have a mid-morning or later flight from Aruba you may have to overnight. The first flights leave Bonaire/Curacao around 8AM and it's about an hour since many of the Bonaire flights also stop on Curacao. Even though it's the ABC Islands, Curacao is the middle one.
Aruba has a dozen shore dives, beaches, nightlife, shopping, casino's etc.
Curacao has 4 dozen shore dives, beaches, nightlife, famous shopping, casinos etc.
Bonaire has 6 dozen shore dives, no beaches (except Lac Bay), not much nightlife, one casino. People go there to dive.
I don't think you could be waterfront in your price range on Bonaire as many of the accommodations are bundled diving/driving/unlt'd tank rental packages with double occupancy rates. Typically around $1200-1800.
Unless you rent something privately on vrbo.com. Sunbelt Rentals also lists some. Just about everybody will have some sort of shore dive package option available also. Staying a block to several miles inland there are inexpensive options - Coco Palm Garden/Casa Oleander or Lagoen Hills are two. I believe just about all their units have full kitchens. I think Lagoen Hills also offers pre-stocking if you're arriving late.
On Curacao either east or west of town you could find something either beachfront or very close to it. Likely a condo/apt. with a kitchen. We've stayed at two, one was $125-45/nt. for a 2BR condo in a resort area 10mins. west of town.
http://www.piscaderabayresort.com/index.php?page_id=2
The other place was 1/2 hr. drive from town, $85/nt. for a 1BR oceanfront (60' above the water) apt. with a minimal kitchen. Drive back to town for just about everything (except diving) from there:
http://www.mydreamapartments.com/Englishindex.html
One I just saw referred was Atlantis Apts./Diving. In town, shop is on-site, shore dive there and some of the better eastern dive sites are probably 5-10mins. drive. IDK anything else about it.
The only AI on Curacao - Sunscape - is near there also but IDK if it's within your budget.
Finally check out anything on
Info Bonaire - The Bonaire Information Site - The Most Current and Up-To-Date Information or
Curacao Travel- Caribbean, Curacao, Dutch Caribbean if you've not seen them.
P.S. U.S. Dollars are the official currency on Bonaire now. Guess where their business comes from.
