Lots of my friends point to Scuba Club Cozumel as a cheaper place to dive. And airfare (about $400 from Cleveland Ohio) is certainly cheaper than the Red Sea or Asia. But Scuba Club is running a special which is $143.75 / per night for double occupancy, which I believe doesn't include the $75 for a 2 tank boat trip, and single occupancy will be more. So about $220 per night or $100 per dive (the per-dive cost going down with more shore diving). About $2000 for a 1 week trip with about 20 dives.
I just got back from the Red Sea, where I ended up on a more expensive group trip, but planned to go alone before COVID cancelled my boat. I would have paid around $1100 airfare but $165 per night or $60 per dive. About $2500 for a 1 week trip with about 20 dives.
Both have nice land based opportunities for a 2 week dive + on shore trip, Mexico is probably cheaper, but Egypt lets me visit anywhere in Europe which has a lot more possibilities.
With the Red Sea, I can turn that into a 30 dive trip adding a mini-safari for around $3000 total. With Cozumel, I am well over $3000 for a 30 dive trip.
The diving is nicer in the Red Sea, and places like Thailand or even Indonesia aren't much more.
Obviously, if I wanted a less than 1 week vacation, Cozumel makes a lot more sense, but I don't see that.
Am I missing something? I might do a Cozumel once just to see a wider variety of places, but I have a hard time seeing this as a budget trip.