I'm with Rick here. No, it probably isn't $38K, but Rick didn't say it was. He said that was his highball estimate because the OP refused to provide any details on existing construction. I mean, c'mon, he works for an engineering company? Remind me not to hire them!
And of course it's a commercial space. You just don't screw around with commercial space, you have to get a permit and engineered drawings. What's under the room, the sanctuary?
My guess is $10K in materials plus permits (varies greatly by jurisdiction), with all volunteer labor. Presumably there is a GC and tradesmen in the church who can pull the required permits. Commercial ain't like a home studio where the homeowner can pull permits and even do most of the trade work himself.
Or if this is being rolled into a larger remodel, perhaps there is no marginal cost to permits and economies in purchasing materials, labor, etc. But then we'd just be guessing, and guessing with no real information.
OP got the advice he merited . . .