Get a used or refurbished one from ebay. The US region 3DS' are pretty expensive. but if you get one from a different reigon for example, a japanese 3DS. There is a slight price decrease. All you have to do is mod it and reigon unlock it.

get a japanese one they tend to be cheaper an in better condition thats what i did and mine's practically mint (save for a small scratch on the top screen) and i only paid 110 usd