Keep in mind that if they are selling an existing model, you probably don't have a choice of brakes. The price is likely for whatever model they have.

I went from rim brakes on my LHT to Disc brakes on my Troll, and my preference is for disc brakes.

I don't really worry about it being serviced in remote areas. In the US, I expect most bike shops will be able to handle either. And if you're so remote that there's no bike shop, then I guess no one will be able to service your brakes, no matter what kind they are. I don't know how common disc brakes are in other countries.