A couple of suggestions would be to provide target budget and whether you are going in low or high season as budget will dictate resort choices. Tough to give spot on options when you say "affordable"; what some consider affordable, you may consider expensive. Having stayed at a variety of places in GC, including the Reef, my suggestion is to avoid the remote side of GC for your first trip. Spend your last, non-diving day driving to the quiet side and check out the Reef; if you like the remoteness, you can do it the next trip.
We travel during low season (April-mid December) and when we want a nice trip, we stay at the Coral Stone Club; all the units are beachfront and they are full condos. A week of lodging alone is around $5,000. When we want a less expensive trip, we stay at the Discovery Point Club "DPC". Most of the units have been remodeled and you can go online, see pics of each unit and choose your unit. They are all full condo, oceanfront units and a low season week is under $2,000 (call direct and ask for specials for best rate). If you want to make it a cheap vacation, you can cook a bunch of meals in your unit. The other nice thing about DPC is that it is 2 minutes from the West Bay dock from where multiple dive boats depart.
We like Living the Dream Divers and 6 days of 2 tanks dives is $510 per person. We usually take our gear off the boat a few days and do shore dives at Turtle Reef, Cobalt Coast & Eden Rock, getting tanks/weights from the on-site operators (2 divers approx. $25 per diver). Rental car approx. $350/wk. So, before food, you can do a lot of diving and stay oceanfront for $3,500 or less before considering food.
As someone else stated, there are a lot of different options for GC across many price spectrums. I'm sure you can go even cheaper if wanted to stay at a dive resort like Sunset House or Cobalt Coast. Just look around based on target budget. Feel free to PM me with specific questions
---------- Post added March 29th, 2014 at 09:25 AM ----------
Just read this and it may help. Post #2 in this thread is spot on with respect to shore diving options in GC. If you wanted to save money, you could do more shore dives vs. boat dives and get plenty of variety. When we were new divers, we learned a lot & got more comfortable by doing dives on our own (in Bonaire) rather than rely fully on a guide off a boat.
http://www.scubaboard.com/forums/gr...e-diving-grand-cayman-cayman-brac-advice.html