If you want to save money, get the enclosure on craigslist (40 gallon breeding tank is the smallest for one BD that you want to get). Sanitize it thoroughly with bleach and water. And purchase everything else new, including the BD. You want to get one that you KNOW how he was handled and taken care of, and you can't really do that off of Craigslist. They can be very sweet socially, but you still won't know how they were taken care of health wise, unless you know what ill health signs to look for. If you do know what to look for in their bones, eyes and skin, then that could be different. But if you are very new to being a BD owner, I don't think I would chance it.
If I could do it all again, I would get one from a reptile show. But I agree, getting one from a reputable breeder is good. Next best would be from a pet shop that specializes in reptiles only, which is where I got ours, but that also had it's downside. It depends on who you talk to and the sales rep you get, that will or will not know a lot for a first time BD owner. I've run in to both at the same reptile shop.
If you get one from a pet shop, try to get one that is at least 4 months old, otherwise the younger they are the more problems you can run in to…they are more skittish and easier to get lost when outside of their enclosure when they are younger. And slower to move (therefore less easily lost) as they get older. The furniture I would also precaution about getting used. They can carry parasites, etc. If you do get the furniture (basking logs, etc) used, be sure to wash fake plants in hot water and bleach, and wash then bake wooden items in very low temp in the oven for about 30 mins to kill any parasites.
Lastly, if you do get anything from Craigslist, no matter what they tell you about the age of the UVB lighting, toss it and get a new one (not the fixture, obviously, but the light itself. The UVB lights should be changed out every 6 months to a year, and you really have no way of knowing WHEN it was last replaced, except for what they tell you.
BDs are very sweet, usually, and are very sociable with their humans.