1) People buy loads of the same card in the hope they will ether go Cr, get a rebirth version or increase in price. This is all done to try and make clintz.
2) People earn money through a load of different ways, Buying packs, winning events, buying and selling cards e.c.t There is a guide here: http://www.urban-rivals.com/en/community/forum/?mode=viewsubject&forum_page=0&id_subject=2108439&subject_page=0#answers onways to make clintz.
3) People put cards on the market higher then the lowest for a few reasons.
- They were the lowest price but people put there own card on at a lower price again.
- There hoping the card increases in price and people buy there card.
- Its a level that people will pay more for E.G level 1 5*, fully levelled new card E.T.C
- They don't actually want to sell the card just show it off.