I think its a combination of high mark ups (which is pretty much a given) and also underestimating how popular it would be. Once they'd started on the stretch goals they had to keep them coming. Also factoring in shipping costs which has had a bug increase in the US (much like us).
I saw someone say Mantic made a loss on the DBO kickstarter. I don't know if that's correct, but I can well believe it, and I wouldn't be surprised if FFP did to.