I dont know if it exists for XP. If it does, please consider you can find a used Imac for less than 300 $. I dont know if it is cheaper than some emulation software, but it will certainly soon pay by itself in saved time.
I'd be surprised if you could get a used, new-style iMac (w/ OS X) for $300. I don't have statistics to prove it, but I'd guess that OS X is making a large dent in the Mac install base. Testing with an "old-style" iMac may not provide as much benefit as you think.
Yes you can emulate the Mac on Windows, but the last time I checked (a while ago) it was only for the very old 68k Mac. I doubt you'll be able to emulate any of the newer Mac Oses. Try this link though: [macwindows.com ]