I first learned about them the last time Jonathan Ward was on the Joe Rogan podcast. If you don't know who Jonathan Ward is, he's the owner of ICON
(website) who I first saw on Jay Leno's Garage. Anyhow he was talking about how he'd like to do one of his restomods on a Volvo Sugga. Sounds like they are really rare in the US and if you wanted one you'd have to buy one in Europe and ship it back. I've seen stock ones
(Like this one) listed for around 45k. To pay someone to do a restomod on one you'd be up into six figures.