Granted, I am a beginner at LAing. But to just load a quilt, backing and batting on takes at least 2 hours. This includes measuring both back and top to find center and ensure neither is too badly out of square. The quilting itself, even a freehand all over pattern like a meander takes more than a couple of hours too. You need to reload bobbins and recheck tension and this time frame is assuming everything goes smooth and you don't have any issues.
Before I got my LA I sent a quilt out to be done by Green Fairy. This was a custom quilt job so I paid 3.5 cents per s/i. When I got it back I was so thrilled and asked her how long did it take as there was so much detail quilting and a lot of SID ruler work. She said she estimated it had about 40 hours in it but couldn't be sure because of interuptions by kids etc.
Sorry to be the bearer of bad news to your DH but he is grossly under-estimating the amount of time it takes to quilt on a LA when you figure all the time besides actual quilting time spent on any quilt. You got a very fair price with batting included.