I purchased an iMac and then a Mac Mini a few years ago when I had some Mac/iOS contract work. They were both second hand, total about £1000'ish. Even then I cringed as I knew they weren't worth it. PC wise, the hardware was way outa date and now their just gathering dust in a cupboard. God Mac hardware is overpriced!
Something I thought about years back was building a Hackintosh but I heard it was tremendously difficult and throught with comparability problems. Also I'm an AMD guy, so this was outa the question on my hardware.
But out of sheer interest, as I no longer support OSX or iOS, I purchased bog standard 2nd hand Intel desktop base unit off of eBay. It had an Intel i7 3770 and was on an Ivy Bridge(both CPU & MB being Intel, makes for an easier installation) mother board, with 4 meg of ram, 300GB HD, 300WATT PSU, in non-de-script black desktop case. £100, not a bad find. Although an i3 or i5 would have been just as good for this. I was lucky, that it came with a free(it wasn't even mentioned in the ad) NVidia GT210 GFX card, which was a surprise as I thought I would have to use the CPU GPU(which works also). It's not an expensive card though, £10-£15 on eBay, actually its pretty bad card but what the hell.
Since I wanted to support High Sierra (Mojave would not use the NVidia GT210 but the installation procedure is the same if I want Mojave) I choose that. The method I chose did not require a Mac to create a recovery USB, its all done on a Windows PC. I just followed the instructions off a website and created and a couple of hours later I had the OSX installation USB drive on an old 8GB USB 2 Key. Booted to that and installed onto the 300GB HD. Resetted the machine and it booted into High Sierra. I may have been lucky but everything worked. It's a full Mac on the screen. It comes up as an iMac 13.3. No incompatibilities, sound, network, keyboard, mouse etc. I can log into the App Store and it is not rejected and seen as a legit iMac.
It was a bit weird, seeing a Mac on a PC monitor but it does work. I've used it various things, nothing serious though, just resting compatibility TBH. Its fast, I hate to say it, OSX is much more optimised than windows, even on this relatively tame hardware its very smooth(Although I did stick in an old 4GB DIMM that was in a drawer afterwards to get 8GB), not a hint of jittering. I have also stuck in(I'm a bit of a tech hoarder) an old 250GB HD and installed Windows 10 on that, the Mac boot menu supports dual booting off the bat so nothing else needs to be done to support a dual OS boot.
It's a time consuming and pretty exact process that had to be done in many multiple steps but an evening can get the job done. Hell if a numpty like me can do it...
But the equivalent iMac (A1419) on eBay today would be, 2nd hand, £750 - £1000 (Admittedly with a screen). My total cost(Excluding some old junk I had lying around) £100.
It was fun, in a nerdy kinda way, to see if it could be done mainly, I would definitely advise anyone to give it a go.
The main reason I mentioned this is I know some of you still want to support a OSX(iOS possibly on other dev kits), so this may be a cheap option for that.
It's also rather, ahem, grey area legal-wise. So I can post the link to the website I used for the instructions via PM if your interested.
Any admins not happy with the post, feel free to move/delete it, no harm done.