Trading a nintendo DS for a PSP?

hello guys I have decided I would like to trade my DS for a PSP and wanted to know everyone elses opinions on if it's a fair trade or not. My DS is about 2 years old but it works perfectly and I was throwing in 3 games ( pokemon mystery dungeon, mario 64, and advance wars dual strike. in return I want a PSP system ( don't care which model) with the charger, battery, and all the basic stuff. games would be nice but I can get games later regardless but first I need the system. Does that seem like a fair trade to everyone else or is my deal lopsided ?