I've purchased some new and some used. If you're super lucky, you can buy new for used prices. IMO, that is the time to buy. For Panasonic, it's during Black Friday. A few years back, I got the Olympus E-P7 with the kit lens and the Olympus 75mm f/1.8 for 899 euros. That's probably the best deal I've ever found for new. In France, you have leboncoin, which is very good too with some amazing deals from people who just want to unload material or just don't understand what they have. When you buy, you have the choice of sending it back. If you know your cameras, you can thoroughly test it. Buying off Ebay is an option too, but you never seem to find good deals anymore (I gave up). MBP is also a great choice, but they're too expensive for some cameras and lenses.