I'd have to disagree with mobo, the tree umbrella is one of the most useful tool I've ever bought. I have 2 different tree umbrellas, a big one and a small one. I assume he's talking about the small one and that's my favorite. I use it for a ground blind, use it for stalking, and it's kept me dry in some really bad weather, rain, sleet, hail and snow. If it's going to be windy and raining, I then get out the bigger umbrella. I have had the wind turn the small one inside out a time or two, but if it's that windy, it's probobly too windy to be bow hunting.
I agree with cheap optics, and at the top of my crap list is the Bushnel range finder, (the $135 one) followed closely by my Bushnell pocket size binaculars,(the $50 one) both useless at least 1 hour before dark. Another big waist of money was the red dot sight. The kind that doesn't have a tube but the window style that projects a red dot onto the window to look like a laser dot. Absolute junk! I tried it on 2 different hand guns and even bought a holster to fit only to find out that open sights were faster, a lot more dependable and much more accurate.
One other waist of money was my McKensy 3D buck target. It takes a crowbar to get a field point out of it and it isn't muck easier to get a broad head out of it. I have to throw it on it's side, put a foot on it and pull like heck to get an arrow out of it. What a pain. It's too heavy and bulky for A decoy and after a short time out in the elements it rots out, the surface turns to dust!
The only other thing I can think of was a pair of gloves. I don't recall the brand but the slogan was something like," the warmest thin gloves in the world." They cost about $20. I tried them one time, it wasn't real cold out, about 40 degrees but my hands were frozen before I even got to my stand. I took them off and my hands were a lot warmer without them than with. Cheap $5 pair of fleece gloves are a lot warmer than these were. I took them back where I bought them thinking maybe they were cold because they were too tight. Traded for the next size bigger and froze my hands again!