Well, jos, you did ask about other places, so perhaps you should look into Roatan. I'm not familiar with the accommodations at West Bay, so don't know if you could find something in your price range there, however, the snorkeling off the point down at West Bay is great! It's a very beautiful beach as well.
Now, what you could do, is find your accommodation in your price range, in West End, enjoy the little village, do some snorkeling from Halfmoon Bay Cabins (you don't have to stay there to do the snorkelling), and also, take the water taxi down to West Bay to do snorkelling there.
There's also a zipline between Westend and West Bay, that your kids might enjoy, if they are old enough.
Feel free to pm me if you want to get some accommodation ideas, or anything else you'd like to kick around.