I was looking on my phone for a spot I could get some cheap pool noodles to make quadcopter gates. I came across this ad on google:

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When clicking the link it doesn't actually take you to $1 pool noodles so I went into Target customer service to ask. The ended up having to sell me $4 pool noodles for $1. I bought a lot! =)

Next I went next door to the Home Depot, went into the PVC iasle and found some PVC Conduit for $1.60. They come in 10' sections but you can use their tools to cut this pole down to a reasonable size.

You'll want a few 5-7" pieces to connect two noodles together for an extra long noodle, and a few 1-3' poles to stick in the ground. The longer your PVC stakes, the taller your gate can be without being floppy.

Feel free to copy that image and take it to your nearest target. You can build 6 gates for around $13.