MP9
Going to add this one into the thread. The seller is looking for £250.00 for an MP9 with a PEQ-15 replica of some description and a foregrip. While this in and of itself isn't necessarily an issue it appears as though the gun doesn't have the CQB bolt fitted (my understanding is that it frequently chrono's above your average UK site allowance without it) and the gun hasn't been touched in 8 years, according to the seller's advert, even going so far as to state it has never been fired within that time period nor did the seller test it at point of purchase.
Let's be honest, there's a good chance every single seal has dried out and probably perished by this stage with the added bonus that the gun itself won't have had any maintenance performed over that period either. The seller claims it is in "good condition" which I would agree with in terms of the externals but internally this is potentially a thing of nightmares.
On a side note, I wish I could remember how to embed ad's.