How easy is it to re-string an acoustic right handed guitar to left handed? Will everything still be in order if it's done correctly?

The amount of 3/4 acoustic electic left handed guitars are quite limited, as you might expect, and i've seen a guitar i want to get but its right handed (i'm a lefty).

Also if i get someone at the shop to do it, it will be like a tenner or so right?

Cheers