It's not necessarily as easy on the pocketbook as you might think. By the time mine was done I had spent almost as much money as I would have building a regular, permanent structure. I bought 2"x6" lumber for the base and used reclaimed lumber and plywood for the rest of the framing. Bought three cattle panels and a bunch of 1/2" mesh hardware cloth to enclose the space. Hardware cloth is not cheap. I used fender washers to button the hardware cloth onto the wood framing, which was another expense. (The zip ties I used only lasted a few months before they started breaking.) And my cattle panels cost $40 each - we didn't have a Tractor Supply here when I built my coop.
The biggest expense I did not figure on was the tarps for the roof. The first tarp cost $40 and lasted less than four months. I finished the coop in February or early March and the tarp had deteriorated so much it blew apart in the first monsoon of the season. The coop has averaged 2-3 tarps/year, so there is an ongoing expense of about $100/year to keep the thing tarped.
If I had it to do over again I would just build a regular coop/run. It might cost a little more to start but it wouldn't have the ongoing re-tarping issue. It would be cheaper in the long run. And it would look a whole lot better. The hoop coop is not the most attractive thing in my yard. But it's what I've got.
Oh, yeah - the hoop coop is MUCH hotter inside than my regular coop/run. That tarp holds in a lot of the heat. Even though the ends are vented and the sides are staked out away from the coop, it feels much hotter when I walk into the hoop coop than it does when I walk into my other coops. It's not as hot at chicken level because the sides are open along the bottom. But it is much more uncomfortable for me.
Just some things to think about before you jump into construction...