the problem you're going to have is that a professional builder will charge for their services.
Not sure how much money you'd end up saving. You would not have a warranty or guarentee, and eventually they'd probably stop answering your calls.

The blackbelt printer - and there is another company who made one - Ah just remembered it was printrbot - who dropped off the radar a couple years ago. That was weird, they were a really succesful company with great machines, universally great reviews and just vanished.
They were the first of the modern belt machines.
Ultimaker's 'thing-o-matic' was a sort of belt printer in that it used a belt for the build platform, but only rotated it when the print was done to start to next one.

Ah - there was a guy around a couple years back who made a delta printer that printed on paper and would queue jobs.
He might be worth contacting. He went as far as an indiegogo or kickstarter.

If I could actually search the forum I could find him, but it looks like bob-the-bloody-pia-web-builder got bored again and the search has vanished unless you want to search the news site - which I don't.