Don't spend 2000 euro's on a commercial greenhouse polytunnel. With an old trampoline frame, you can make a sturdy plant tunnel on a low budget.

polytunnel greenhouse old trampoline frame upcycling
DIY greenhouse polytunnel, made from old trampoline
Inside view of the polytunnel trampoline upcycling greenhouse
Trampoline frame made into greenhouse
End result of cheap poly tunnel from upcycling an old trampoline frame
Welding on the trampoline frame for the greenhouse
Trampoline DIY greenhouse polytunnel frame