I just checked my catalog. A guide has the moldy shirt and dress listed for 400. I went into the store and checked the price and the guide is wrong.
Moldy shirt is 40 bells
Moldy Dress is 40 bells
Bandage and doctor mask are 80 bells. There could be more that are 80 bells
Pink or Blue PJ bottoms are 240 bells
Black ankle socks, dress socks, white lace socks are 120 bells
Slipper are 320 bells
The cheapest items would be the ones your villager started with because those are free. Also the balloon hat can be free if you hit it with your net.