Hey Andrew, I'd recommend building your own as it's so simple and much cheaper. I originally built a small incubator out of a Styrofoam cooler, a computer fan, light bulb and socket and a thermostat. Because I'm Canadian, I had to pay an insane amount to get the thermostat shipped from The States, which you don't have to worry about. It was still under $60 with a quail tray and easily accommodated 96 quail eggs. I had the tray pivot on a rod through the side with another rod coming out the top to tilt it up and down. Worked like a charm, though it needed manual turning.
This year I wanted a bigger incubator so I bought a 2x8 sheet of 1.5" XPS rigid foam board. I made it 2x3x1' high and you can get that out of 1 board. I had the stat, fan and bulb mounted to the top of the cooler so I plopped that on top and used a spare piece of XPS for the rest of the top. This time I used cartons and turned them manually, which sucked but worked fine. I don't know how much the XPS is, but it'll be pretty cheap compared to buying one. You could also get an automatic turner and put it in, which I'll do. I had around a gross of eggs in there with room for water containers for humidity. I did have to go to a larger fan with the bigger incubator. I initially had horrible hatch rates which I originally attributed to temp fluctuations as I'm in a camp with only a woodstove to provide adequate heat. Turns out it may have been the eggs but I'll never know. I ended up using a 175W heat lamp bulb in there and had ok hatch rates with it and new eggs.
I think I'll make some changes to it this year; I'll see if I can do a rolling turn on the bottom and then a platform above that for hatching. I haven't worked out how many eggs I could fit on the bottom, but I could always turn on the top floor too in a staggered hatching. It might take a bit more headroom than I have, but I can always add a strip to the top. I'll also but more insulation around it. I think I should've gone 2.5" thick, but you don't have to if it's not going to be -25 or so where you keep your incubator. I bought a couple of digital stats for about 13 of our Canadian dollars each, so I'll use of of those instead.
I have been thinking of finding a broken freezer to make a larger incubator from and, as luck would have it, my upright packed it in a few weeks ago, so there's that. I don't think I'll need it this year for hatching, so I'll just keep using it as a freezer outside and putting ice in it if we have warm days this winter.
What is your plan for hatching? Are you going to be collecting eggs for 7-10 days and then do batch incubations? I think that's what I'll do to avoid constant hatching. This year I bought 10 day old commercial poults and brooded them with my chicks and ducklings. The poults seemed to learn a lot from the chicks about scratching and later foraging, though the poor girls had their toes and beaks clipped. I'm going to do a hatch of chicks first so they're a week or so older than the poults to give the chicks a bit of a head start.