OK, I'm gonna take a SLIGHT objection to your logic. You posit that a Mac mini can be had for £201, which is the base price (£339) of the machine, less the cost of iLife (£49) and the cost of Tiger (£89).
Unfortunately, the problem is that iLife is FREE with the purchase of a Mac mini. So is the OS, either Panther or Tiger. As far as I am aware, you can't buy a Mac mini without either of these items... and you can't take the OS from your Mac mini and install it on a different machine (not legally, anyway).