I don't make 'em but I've often thought about doing so, especially since I use anywhere from 400-1000 per year on my survey and engineering jobs. What I buy is what is available locally, which is a full 1" square stake, 4' long, sells for 99 cents per stake at the local lumberyard/ripoff home center. A place further up the road sells that same stake for $1.20 each. The mill I used to buy the stakes at, before they closed up, was selling at 25 cents each in quantities of a thousand, 30 cents for 500-1000, and 40 cents for 500 or less.
As far as species, I find birch and ash 95% of the time, although the latest five or six bundles I bought locally were cherry. Maybe that's why the price was so stupid. Anyway, they were totally covered and saturated in white mold, so bad that the bundle had to be beaten apart to separate the stakes. Plus they were wet so we couldn't write on them.

I did find a bundle somewhere, I forgot where, that was 1" by 1-1/4" by 4' long, and the wider sides were planed. I would have paid a buck or more per stake, happily, if I could find them again. Perfect size and condition to write on and they were dry.
They way my grade stakes get used, as long as they're DRY, even pine works. For hubs, which are 2x2x18" long, I use white oak. I get heart cants from a local mill since I don't have white oak readily available, and I resaw the cants into 2x2 and point them. The hubs tend to stay in the ground a long time so they get a hard, rot resistant wood.