Delamination is a bad sign, no doubt, but there are degrees of damage and of causes and of concern. I myself would not automatically write off any motorhome in your price range that has any hint of delamination, but I would be cautious and investigate as thoroughly as I could.
Frankly this looks pretty bad to me. The seams or corners at the ends of the roof have leaked a good bit, it would seem, and likely you have some significant wall repairs ahead of you. I would guess that the side walls of the cabover on the inside are soft and quite possibly the bunk board is, well, bunk, and a good chance the curved carpet covered bit that forms the front wall quite thoroughly soaked through. If the roof decking is soft for a good portion of the roof, that suggests that the roof and ceiling structure also might be nasty. The price seems high for the probable level of damage; I don't think this is a good deal.
For what it's worth, from what I can find online the layout is very similar to that of my '98 Coachmen Santara 315QB, and I think it's a very nice and usable layout. The kitchen space is relatively large, with some actual counters even, and I actually appreciate not having to deal with slidouts; just park someplace level and you're set up to camp for the night.
