Could be a whole lot more than it is. The graphics, good, but individual items don't need to look the exact same every time - have a small selection that's randomly chosen from. Sound is something to consider - none is safe, good sound adds to the game, poor choice may push away interested players.
Might want to expand this out. Someone who compulsively has to change locations every month, week, however long. They have to make enough to pay for hotels, food, etc, which is a fixed rate. They arrive in a location, go to garage sales, foreclosed lockers, businesses about to shut down, abandoned buildings, and they grab what they can bring with them. Then, they have to find the right place to offload - pawn shops will take almost anything, but rarely give top dollar, while specialty shops are harder to find, and take time not just to get to, but to haggle with.
Turn it from a one-week rush for cash, into a globe-trekking lifestyle. It could be quite fun to make. You'd have to research different cultures, but if the player's character only spoke a limited set of languages, that would limit their travel abilities - or severely dampen their haggling capacity.
This game is currently 'interesting'. If you want to bring this one to the next level, add in a few extra days, a bit less predictable results, (The red necklaces are always worth 50. But if they have different pictures, some overlapping with less valuable items...) and frankly, a story of sorts. Why is this girl the only one at this sale? Is she the only one who can find the location, or is it a test to get into the family business?
Probably the most important change, would be to add a simple prologue. One that, perhaps, changes based on how well you did - score well enough, get a picture of a pile of gold or something. Simple to do, but rewarding to the player.
Good job on this one.