I got a FANTASTIC deal on a souped up 13" MacBook Air (which had been partioned for a dual boot) so am selling my 11" Air and MacBook Pro. No problem. I wipe computers and reinstall the OS all the time.
WELL, not since Lion. My first MacBook Air came with a USB stick that you could use to boot from, and you can still make those---but only after you've already downloaded another copy of the OS. What kind of new hell is this? Also, I could get none of the methods to work, so it's mainly theoretical.
My new MBA, which had been wiped and partitioned, had no recovery drive, so I did download a new copy, reinstalled, and all was well, although it took a while and made me a little sour.
The two I'm selling? Hugely different story. The only option there was to boot from the recovery drives, wipe the hard drives using Disk Utility, and use Internet Recovery. This process is painful. It is slow (8 to 32 hours) and has not even completed on one of my Macs. It just quits and says it terminated. This shit is what I would expect from Windows.
No problem, said I. I have a DVD! A physical DVD of Snow Leopard that I can boot from and install that and then let the buyer update. No. Booting THIS Mac from THIS DVD creates a kernel panic. You can't even buy a DVD or stick drive with Mountain Lion on it, and on one of my Macs which did not ship with Mountain Lion I have to enter my App Store ID and password to restore. Which I don't like but I literally have no other option except to doom my buyer to going through this idiocy, which frankly would make me decide an Acer might not be so bad.
Granted, until all this laptop swapping occured, this has not been an issue. My Macs have all been extremely stable. The ONLY times I have needed access to a clean OS have been when wiping and selling a computer. But this is a terrible system. I suppose if this try at downloading to the recovery drive doesn't work, I can download YET ANOTHER COPY of Moutain Lion through the App Store to my working Mac and try again to make a bootable USB drive. But this is ridiculous.