Recettear - Capitalism, Ho!
This is a cute little indie game that came out last year. You play as Recete, a young girl who (through a story involving a crazy father and loan sharks) ends up commandeering an item shop in an attempt to pay back her father's huge debt.
Gameplay is a combination of fast-paced haggling, market-watching (anyone who's played a trading game will be familiar with this) and dungeoneering. You can hire adventurers to delve into ancient ruins in an attempt to find rare and valuable items for the shop, or you can simply play the markets. You have 30 days of in-day time to repay the debt, so it's fairly fast-paced and you have to use your time efficiently. It's even more difficult if you want to see all of the plot arcs with the side-characters played out.
I recommend you buy this game from Steam.