Replying to Buying a gently used camera

so i'm pretty set on buying a panasonic hdc-sd90k. i have a gopro, and i'm looking for something for more traditional shots. 1080p60fps is just what i'm looking for, in a small relatively cheap package with nice features.

anyways, what are your guys' opinions on buying camera slightly used from ebay? my mom thinks that i should stay away from it in case something doesn't work properly, but i feel like ebay is generally pretty secure. there are camera for sale there there are atleast like 100 dollars cheaper than anywhere else on the internet, and being 15 and all i really don't have much to spend.