Martha, most of that cost is probably shipping. A jar like the one Amazon shows should cost about $10 or a little more in a grocery store! If you ever get to Michigan, especially "Up North" Michigan, go into a local grocery store and look for the jars sitting on top of the meat counter! Should be easy to make however, just get some ring baloney and add a vinegar and water mixture, plus some pickling spices.
Also, a screen dryer vent cover might be dangerous because lint would stick there and might be a fire hazard. You would have to clean it out weekly. One of my cousins had a vent fire in her laundry room about 15 years ago, and it really smoked up her house. Luckily, no structural damage, but had to repaint the entire inside and replace some furniture.
And, birds certainly can be dumb. I had one that kept trying to build a nest under my porch in my old condo. She was a terrible nest builder, however, and more sticks would end up on the porch than in the nest. And every year, it would eventually fall down, with or without eggs in it. But every year, the same bird would be back to try again!!