Some chiropractors give a cash discount. It usually runs about $150-200 for the initial visit, but then I've paid in the neighborhood of $30-50 for subsequent visits.
Yes, there are some issues that need some regular work for a while, but not forever. It depends on the problem. There are some problems you have to see a regular doctor for regularly. The difference, to me, is that the regular doctor can rarely fix a problem. He can usually only treat the symptoms. The chiro can actually help fix a lot of problems.