LOL
I can tell you a few that I didn't buy
at the first MK a guy turned up with a boxed NOS blue set of DX cranks , he wanted a fiver for them. no one bought them

I was offered a NOS haro freestyler for 80 quid, I refused.
full bikes that would sell for 2k now for peanuts
I had 3 r gusset Raleigh pros , all sold for peanuts
I had offered to me a VDC long for 200 , a DB HL turbo for 150
I didn't buy shit loads of stuff over the last 17 years that I kick myself for
but hindsight is a wonderful thing