So, spotted something that I liked better, even though it's probably not the best for my room--Provincetown by Beaulieu. It's a Berber carpet, and has a pattern of faint squares formed by different loop sizes, not by color. It's not a uniform color but has some speckles of dark and a few blue yarns in among the base color, so hopefully detritus tracked in the patio door won't show too badly. Disadvantages: the loops of a Berber (or any closed loop carpet) might get snagged by cat claws, and the pattern of different heights will be harder to vacuum. But you know, the closed loop carpet in the study isn't badly snagged, and I generally don't vacuum my own carpet.
Took a sample home, compared it to the stuff from the wholesale house, and decided I liked it. Went back to the wholesale house to return their samples and asked about the HD piece--turns out they carry it, but it's called CityBlock, and the colors are all named and numbered differently. This is so Home Depot can pretend that they have an exclusive on the carpet, I'm told.
Now, on to pricing. I thought the wholesale house would have a slam dunk, and so did they. But no: HD has a sale on. The price is $21.34/sq. yd. including pad and installation, but you want to upgrade to the thicker pad with the stain shield layer for another $1/sq. yd. OK, make it $22.34/sq. yd. The sale is 25% off that, so $16.75/sq. yd. or so. Called the wholesaler, who priced the carpet at $12.42/sq. yd.. Their superior padding (add another 1/16" to the better HD one, I think) is $4.29/sq. yd. Wait, we're already at the HD price, and haven't gotten it installed yet.
So I call an installer for some ballpark numbers, as the wholesaler says she can try to find an end of a roll that would be cheaper. Installation base cost is $4.50/sq. yd. to install a Berber carpet. But add $1 for the pattern matching, $1 to remove the old carpet and padding and haul it away, and $1 if they move the furniture. So that's $7.50/sq. yd.. And there's a flat $25 fee to come measure the room, which isn't required, but puts the burden of ordering enough carpet on them. Betsy's recommended installer might do it cheaper, but he's in the hospital having just suffered a mild stroke.
I think I'll go to HD tomorrow and buy the carpet.