I have a 4yo desktop with one of the original Intel Core 2 Quad CPUs, which is getting a little elderly. I primarily work in Windows but have a 2007 MacBook; I recently started supporting iOS so I need a Mac but this too is getting rather sluggish.
I'm not bothered by super high-spec PCs so would probably look to spend £500 on a new desktop (or $500 in the US, it's roughly comparable), and the cheapest Mac Mini since the cost of iMac is hard to justify for part-time use.
But I wonder, would getting a more powerful Mac and using it for both (using bootcamp, not virtualization) actually make more sense? A top-spec Mac Mini is a big price-jump from the lower end ones - £400 more - but still cheaper than two machines since you don't get much of a desktop for £400. The only missing bit is the discrete graphics but modern integrated GPUs are so much better than they once were.
Anyone care to throw in any opinions or personal experiences that are relevant?