About a third of the cost of most trips. Almost all flats in the Bahamas will have bonefish on them at one time or another. They averaged 3-4 pounds and a few were over 6 pounds. I had shots at plenty of fish over 8 and 10 pounds but unfortunately they evaded me. There is always the possibility of going and not catching fish even if you went to a lodge.
Weather is the biggest factor.
Research your best options, its pretty easy. There are map companies that have maps of the islands which will show you water depths and roads that lead to the water. What you need to look for are areas of shallow water. You could do it without a map but it definitely helps. There are some other items that could help but those are the necessities.