We were in a similar situation re price/availability, and looked at conversations from the better approved converters, but they made no financial sense as once a half decent base spec van was used they were as much if not more than a list price Coast. And the residual will never be as good as a factory built Cali. So we bit the bullet and brought our one year old Coast! I think the greatest risk when the current high price bubble breaks for camper vans & motorhomes will be the T5/T6/T6.1 conversions as they are everywhere - Cali’s are still a relatively small percentage of all the vans out there & very highly regarded.
We have lost a few friends & family members over the last couple of years & some went before they got to do what they were always talking about doing, you can’t buy time.