Simon, you need to consider the following. Trade insurance (most policy's cost £1k + Trade plates (unless you are planning on taxing each car) If you are working from home you will need planning permission (it won't be long before your neighbours report you) If you are going to be working from premises you need to work out your in going costs. warranties (whether you will use a 3rd party or be covering the warranties yourself) Prep (repairs/mot's/bodywork) unless you know a couple of tradesman or can put lots of work their way you will most likely be paying retail prices. With lot's of overheads, and a lot of time and money going into a car to bring it to retail standards it's not as cut and dried as just buying it for 500, selling it for 850 and bingo 350 profit, unless your lucky, and don't forget the customers who will try and beat you down with a big stick. 5K is a small budget for this game, not impossible but hard, if you get a lemon you won't have much to fall back on. It might sound like I'm trying to put you off but after considering the above if you feel it's viable for you then I wish you every success, we all have to start somewhere. Kind Regards.