DjDiverDan
Contributor
There are cheap hotels in town - you should be able to get a room at La Casona Real, about 3 blocks straight back from the North end of the Plaza, for about $35 a night, and it even has a pool and AC. If you don't need either a pool or AC, you can do cheaper - maybe as low as $25 a night for your own room. If you go to $40-$45 a night, you can get in at either Suites Bahia or Suites Colonial (no pool at either, but a great breakfast buffet at Casa Mexicana included).
For an excellent "no frills" Dive Op, I recommend Dive with Martin. If you do a 5-day package, you should be able to do all 5 days for about $300, maybe a bit more. The only real problem is that Dive with Martin is located at the International Pier, at the South end of the south hotel zone (just past Casa del Mar, Park Royal and El Cid/la Cieba), and it doesn't pick up in town, so you'll have an 80 Peso taxi ride to and from diving if you stay in town.
For an excellent "no frills" Dive Op, I recommend Dive with Martin. If you do a 5-day package, you should be able to do all 5 days for about $300, maybe a bit more. The only real problem is that Dive with Martin is located at the International Pier, at the South end of the south hotel zone (just past Casa del Mar, Park Royal and El Cid/la Cieba), and it doesn't pick up in town, so you'll have an 80 Peso taxi ride to and from diving if you stay in town.