You may not want to use it for sewing in the traditional sense, but you can tell him that you can also make your own quilted fabric for other projects such as duffle bags, purses, hunting vests, placemats, coats, and save lots of money by not buying it ready made. This would also allow you to chose to have a real fabric (not that nylon or paper stuff manufacturers put on the back) so it would be warmer and sturdier. Just imagine how cozy it would make a jacket if you quilted two pieces of fleece together.

I can on mine. I have a Juki 2000-TL-Qi. I would think that if it has feed dogs then you could, but I'm no expert.

As a note, I don't usually piece on my Juki. I do all my piecing and "regular" sewing on my Singer. I do all my quilting on the Juki.

You might want to approach it another way. Several years ago I bought a high end machine with a large harp for $4,000. I looked at upgrading for newer features and a little larger harp area which would have cost over $9,000. My Baby-lock Tiara II, a sit down quilter with a 16" harp cost $5,000. I lost absolutely nothing but a little space in my sewing room. I realize that prices vary around the country, but I think the comparison will be about the same wherever you are.