Never played a Pathfinder, myself, but yes, you're quite right, it will give many more tonal options and will sound much better than the weedy little freebie amp. I quite like the little Roland Cube amps, too, personally. They do a tiny 15W version, that is only £59. The slightly bigger 30W is alot more money, but has built in effects, which is worth considering.
Anyway, depends on what the shop sells, really, as you'd be best to buy it all off one place- they are likely then to bung in the bits and bobs (cable, strap, plectrums) for free.