A comment
I am a summer resident with quite a lot of experience. All my seedlings begin their life under greenhouses. I have 4 of them. Periodically, you have to buy or change arcs and covering material. Here came the moment when one of the greenhouses completely failed due to the natural wear of all structural elements.
In the building goods store, I looked after a small greenhouse. Completely plastic with agrospan covering material. In all respects, including cost, it suited me.
There is nothing unusual in assembling the fields of operation, which is what advertisers like to lure gullible summer residents. Everything is standard, including the extremely low quality plastic pegs that I even started using. Instead, fittings with rubber gaskets are simply clogged into the pipes so that they do not hang. A piece of reinforcement is 28 cm. 10 goes into the pipe, 15 into the ground. Enough to secure the greenhouse in the ground. It is not necessary to paint the fittings, even with constant dampness, the metal rusts extremely slowly.
pros
reasonable cost, high-quality covering material, lightweight plastic arcs