I have only recently got into Paintball, and I have been keeping an eye on Ebay, as occasionally paintball gear does come up, and there are opportunities for picking up some good second hand stuff. The only limitation to Ebay is that you cannot buy/sell markers on there, but for clothing, and padding it could be a good call, but the quality is likely to be variable, so if I'm in doubt contact the seller and ask questions.
I have also been keeping an eye on the UK on-line paintball shops as again if time isn't an issue items come up for sale at a decent price.