I have 2 compost tumblers (1 used end-for-end tumbler for $50 and 1 horizontal spinner on sale for $100) and I'm not impressed. They don't speed up the process much for me. It is difficult to regulate the moisture and the compost they produce just doesn't have as nice a texture as the wire bin compost heaps. If I turn the wire enclosed heaps even 1-2 times I can get compost as fast as the tumblers and MUCH nicer texture. I haven't done any nutrient tests, but the stuff just looks and smells better from my heaps than from the tumblers. I would say - don't waste your time and money on tumblers.
Just use some wire fencing, heavy chicken wire, salvaged pallets, whatever comes to hand and enclose 3 areas, each about 3'-4' wide and tall. Fill bin 1 with your layers of greens and browns, when it's full, turn it into bin 2 and start refilling bin 1. When bin 1 is refilled, turn bin 2 into bin 3 and the newly refilled bin 1 into now empty bin 2. Start filling bin 1 again. When bin 1 is full, bin 3 (which has been turned twice, now) should be ready to use (depending on your time frame and how fast you refill bins). Start using bin 3. When bin 3 is used up, bin 2 gets turned into bin 3, bin 1 is turned into bin 2, refill bin 1, etc, etc. You will produce FAR more volume with this system than with tumblers - which work better as all in, all out systems, and take at least 6 weeks or more for me no matter what the weather, how often I turn, etc. I think composting works better when the material is in contact with the ground so bugs and worms can help work the piles. Mother Nature's composters are better at it than we are and if we let them help us, things go faster than the relatively sterile tumblers.
I tried a little experiment of filling my tumblers with some manure - cow in 1, horse in the other. I moistened (it was pretty dry), I turned, I re-moistened, I turned, etc, etc, etc, and it still has manure odor inside clumps that I reach in and break apart. I started this last fall. My wire bin I started at the same time I've already used. The wire bin I started nearly 2 months later I'm getting ready to use. I did not turn these particular wire bin batches at all. They are/were a bit chunky since I didn't turn them at all through the winter, but they still produced some nice compost. The tumblers are fairly ready and I'll probably put what they produce into the bottom of the next raised bed I'm building, but I won't mix them in the top layer where my veggies will be growing, only in the deeper layers (about 14 inches under the surface). This should keep the stuff from burning roots (remember, I just used manure, no browns in this particular experiment). I'm debating getting rid of the tumblers. They take up nearly as much square footage as a wire bin and produce less volume of compost. Just FYI, take my words as a factor in your decision, but things may work differently for you.