[ale] [OT]-ish Cheap unlocked GSM phone

[Adam]

Hi-o,

My gf's Samsung X497 flip phone is dying a horrible death, and I'd like 
to locate a replacement, but I'm pretty mush a novice when it comes to 
cell phone types and compatibility.

I think the phone is just a plain ol' GSM phone, so is it possible to 
purchase an unlocked GSM phone and drop her sim card in? If so, any 
suggestions on where to find one at a reasonable price?

Or, does anyone have suggestions about where I might start to educate 
myself (aside from wikipedia)?

Thanks,

Adam