The best advice I can offer that’s not already been offered is to never feel under pressure to ‘grab a bargain’ where second hand cameras are concerned.
There is a massive market for them, and huge supply for everything you could want. Whatever you’ve seen today, there will be a dozen available again in the near future so you can take your time and evaluate the best option without having to rush to grab it before it’s gone.
I would also strongly advise you not to buy from anywhere that isn’t a recognised dealer in second hand cameras. You can find lots of cheap DSLRs in those electronic pawn shops that have sprung up on the high street. They’re no cheaper than the reputable dealers but will almost certainly not help you if anything goes wrong.
Park Cameras, Wex Photographic, mpb.com, Ffordes, Clifton Cameras, Wilkinson Cameras to name the main dealers, will all have lots to choose from and offer you a six month warranty on whatever you buy.
As for the camera you’ve cirted, I can’t help you I’m afraid as I know nothing about it.