Does your wife dive? I have two affordable suggestions on this side of the world but Don't go to Roatan if she doesn't,
On Roatan you should be able to rent a house for around2/3rds of your budget. The farther from the beach the cheaper. Boat Dives (it's all boat diving should be under 10/$300 if you book 2 months worth or so. Food can be street food to obe of the best restauarnts in Cental America - Ooloothoo.
It's a tropical island but I did not think the market prices were terrible - there are 2-3 large food stores in the French Harbor area, If you stay in/near the West End you can walk to everything except the markets and cabs are cheap. You could probably arrange for a daily pickup if you are a little inland - we had a van driver who picked up our group anytime we wanted to go across the island, I'd look in two areas, The West Ebd or Half Moon Bay on the linked websites. West Bay would also work. there's less there bu the beach is nicer. There's a daytime water taxi between the 2 areas - they're about 3 mi apart. With a car Sandy Bay Rentals are an option. You'll see alot of Lawson Rock properties which is a bice, newer community but about 5 miles up the coast from everything.
Long Term Rentals - Roatan Vacation Rentals & Property Management
Roatan Property Management and Vacation Rentals | Roatan Property Management and Vacation Rentals
I rented Sea Lodge from them. Nice house great kitchen about a 10 min walk to the West End. No beach it's on the ironshore.
Again Don't consider it if your wife does not dive - most of the non-dive attractions are pretty weak and she'll be bored,
Downsides for us from the west US - Flights are unreasonably high - around $800 rt.
And there is a kot of BUGS eveywhere, Mosquitoes, Sand Flies, Sand Fleas (they bite) and some I've never seen b4 caught in the bug zapper. DEET (Deep Woods Off) worked for us,
My other suggestion is Curacao. It's below the Hurricane Belt so you can go all year. To save money there are 60 shore dives along the west coast, most are nice beaches with on site dive shop and some food option. Downtown is the famous shopping area (there's two) nice restaurants all over and good markets including an outdoor one that sets up along the south side of the harbor in Willemstad.
Much of the better diving is in the quieter west side and you will need a car. Flights for us were very reasonable compared to other Carib destinations.
www.curacao.com lists everything,
My buddy's wife was a native. she kept her house when they moved here. 3BR in a neighborhood about 5mi from downtown. Sherents it for $1500/mo. to along term renter. Some of the "Resort" areas like Lagun. Coral Estates, or Westpunt (about 45mins away) are very quiet at night yet all have dive operators.