@TheMagicM
The Mac Mini is a great starter machine for OSX, I started with a G4 version.
But if you do plan on getting some more horsepower for a desktop, I highly recommend looking into a hackintosh.
For $700 (CAD) I built a Quad core, 4gig 800mhz DDR2, 1TB, 512MB 8800GT, 850W psu power house in February of this year and is awesome compared to the mac mini. Only thing is there is a bit more maintenance when software upgrades are available, but worst case you can always get a EFiX (but only works with specific Gigabyte mother boards)
As for every one beating up on you about going into to a store to check our hard ware, ignore them. I do it all the time but I end purchasing from where it will suit me best (just as in your case).