Yeah, it's not cheap to have any significant modifications done at Hallmark. I believe Bill quoted us around $5K for a new lift system. I'll just replace the tracks myself and get a couple of new hand cranks if the teeth continue to wear down, and pat myself on the back for raising the roof using good old fashioned elbow grease.
Having a camper that started its life with a composite roof (08 or newer) is probably your best bet if you can afford it, but a used older Hallmark with roof replaced after 2008 may be significantly cheaper. Not sure if you can reliably inspect for water damage, though, without tearing into walls (which the seller would not likely allow).
We found ours by searching "All of Craigslist" rather than waiting for someone else to post an awesome deal on the used camper forum. It's worth looking there too, but the really good deals posted there tend to go fast. We considered ourselves fortunate that we only had to drive 450 miles to get ours.