it was possible to trade items a long long time ago

it was in ob when the shop were integrated in the game, but the there were a lot of paypal scammers that bought items in the shop and sold them for ingame cash in their stalls.
like backpacks for 1m
masters mistake 800k
stat reset 300k
and so on. when you you´ve played from the scratch you could get everything you want

i´ve got like 300$ items from that time XD
but then they changed the items and make them non tradeable - and from that time on you can´t exchange shop items.
hope i could help you!