You have barganing room with either, but more so with private sales. There's pros and cons of each.
Private: more barganing room and often more trustable then a used lot. More even negotiations. Cheaper, and no GST.
Dealership: Can buy warranty, often cars in better visual condition, also legal recourse in case they rip you off. There's also a lot of laws in BC dictating what dealerships can and can do, but not what private individuals can.
Check my reply in your other thread to see some sites to check out to get information on how to deal with dealerships here, but generally, with used dealerships it can be hit and miss. I've never used one, so I can't really tell you about any in paticular, but a lot of the ones on kingsway seem to be ...well, typical used dealerships.
Honestly, the best bet (although possibly more expensive) would probaly be to deal with a new car dealership or automall. They have used inventories they get through trade ins, and often have a higher standard of quality with what they're going to sell.
Beyond that, the absolute best place you could probably go if you can afford it is the Budget used car dealership in Vancouver. Sorry, I can't remember the adress at the moment, but it's one of the highest reccomended places to get a used car in Canada. The thing is that they're previous rental cars, and they're all pretty recent models, so they may not have what you're looking for (and they don't show the majority of their stock on the internet). But they are ICBC reccomended, all cars are BCAA inspected already, and the reports are readily available. I'd check them out.
