(1) Bought an A1200 with a 120Mb hard drive - cost around £600 IIRC. The company closed shortly afterwards and never cashed my cheque! After waiting a while I used the money to buy a 68030 accelerator.
(2) Bought a "box of misc. computer parts, floppies etc." off eBay for £20. When it arrived it had (amongst other random things) five or six 386 / 486 motherboards with CPU, RAM and everything, a PC RAID controller with a 40Mhz 68030 on it and (ta-daa) ... 300ish original Amiga game disks
Paid EUR250 for an 060/PPC card to a guy advertising on a well known Amiga classifieds site, but he was a total rip off merchant and I never saw a card or my money again