I no you didn't buy it but engine price's vary massively. When I was in need of an engine last year I was having quotes of anywhere from £700 to £1200.
I then found one for £400 and while waiting for a lift to go and get it I was having my usual look threw eBay and another had just been put on 10 miles from my house. Rang the number on the add and got it for £100
yes you read that right!
Obviously it was an absolute bargain and will probably never happen again but if anyone is ever in need of one then don't just jump for the first one.