A friend did Fundies a couple of years ago with an instructor that came in from out of town at a dive location about 90 minutes away. All costs in USD. $600 for class fee, IIRC. About $1K for other stuff like lodging (everyone shared a house), food, fills, some gear add ons. Plus four days of vacation time. So $1600.
Any recreational classes done at the local dive site won’t require you to take the time off work (classes on weekends), lodging if you don’t mind driving 3 hours round trip each day, can do class in rental gear or stuff you already have.
Edit: maybe it was 5 days? Can’t remember.
So I took the time to check this out. Now, understand, the prices I am quoting from doing a very short internet search, are all about in the "ball park" price wise, some a bit more, some a bit less. And this is in Ft Lauderdale, where a lot of the "open water" dives are from the beach, which saves the diver the cost of the boat dives. Most shops included "everything" in basic open water certification, after that, materials, boat trips, and gear were all extra, so the prices I am quoting are for the class itself, pool sessions (if any) and beach dives:
$695.00 - Basic PADI Course, live instructor, with 1 boat trip (beach dives are “free”)
$705.00 - AOW – does not include rental gear, (not clear if boat trip is included)
$175.00 - Peak Performance plus course materials and rental gear (boat trips not included)
All GUE classes will certify you in Nitrox, PADI does not, so that is an addition fee, of about $150.00.
By my calculation, to get to where GUE Rec 1 or Fundies will get you, you will have invested about $1,700.00 +, not including transportation costs of getting yourself there.
I did find one shop in Ft Lauderdale that had a basic PADI class for $179.00, all "inclusive". Again, you get what you pay for.
Let me know if these prices are "way off". I did think the AOW was a tad high, but all the cheaper quotes I could find were silent as to what was "not included".