I've found it's worth while looking through a whole bunch of PC magazines each month, particularly PC home/art mags, because some give you complete free versions of software now and again. I've managed to obtain fully working versions of the following applications in this way...
Painter 3 (excellent natural media prog)
PaintShop Pro 4 (very good all-rounder with some Photoshop functionality - and I used it to upgrade to PaintShop Pro 5 at a reduced cost)
Adobe PhotoDeluxe 2 (useful for some rough-and-ready filtering effects)
Macromedia Extreme 3D
A few of the above came on PC Format mag cover CD's, but there are other mags too, like Computer Arts. I don't know where you're living, so I don't know about specific mags you can get - or even whether they carry full versions of software. I'm living in the UK.
They were not current versions even when I got them, but they just cost me the price of the PC magazines at the time. In fact, I rarely buy a PC mag unless there is a useful free full version of an application on it's cover CD. Why pay a small fortune for the most recent versions of software if you can get their predecessors for next to nothing?
Just keep your eyes peeled every month.