A garage/ loft/ spare room full of cheap (sometimes ) crap that no-one wants and you'll be stuck with . Be warned.
You'll soon learn how to build up said crap into a useable bike that will shake you to the core if it's an mtb
Enjoy,
as soon as your old part become surplus to requirements, sell them. otherwise you'll find a pair of brake levers lying around and you start to build a bike around them!
oh and if you sell anything on the forum here, then make sure it has a price.