I am going to try to show you how I built my first Disc Golf Goal with parts I got from Lowes for around $75! I think it turned out pretty decent. It's within the regulation limits I found here, is sturdy, and most importantly catches discs!
I'll do my best to explain what you'll need to buy and how to get it all together, but unfortunately I did not take pictures of the process. It shouldn't be hard to figure out by looking at the pictures I attached, if you have any questions please ask in the comments. I got the basic idea from other more detailed posts on this page, and just tweaked it with things I came across. Hope this helps someone!
UPDATE----->>> after about a year of use its still holding up well. The only problem is, at the top where the chains are hung through the holes around the trash can lid, two of the holes broke through. I'd recommend putting some washers or something in there.