Last week there was an auction through an industrial auction site that I've used for lab kit in the past. they have all kinds of things, including some stuff being sold off by ITV - the UK television company. Included in the sale were a bunch of Powermac G5 ali base units starting at £10 each (=£20+ when you've paid fees, VAT, delivery etc). I'd always wanted one of those cases, because they look lovely, but with a view to gutting and putting some worthwhile hardware in there instead of the PowerPC based stuff that's too old now.
I had to walk away from it, but it was hard.