I was being sarcastic when I said to go out and buy DSD's. From the looks of things you are just starting to build your spread. Of course you can't run out and buy decoys that cost that much. I sure can't and nobody expects a 16 year old to. That being said, you ought to build up your spread if at all possible. I takes time, I add a couple pieces every year. Get a six pack of full bodies for christmas, a blind for your birthday, pick up an extra lawn and use that money for hunting equipment, etc. Don't feel like you have to have the baddest spread to kill geese, you don't.
You have the biggest ingredient already in place.........location. If the geese are setting up and flaring, they saw something like movement that scared them. If they are just sliding off like they just aren't convinced, you have something out of place that needs a little tweaking, but isn't bad enough to scare them. If you spent alot of time on your silos, they probably aren't that bad. I've killed over some pretty crudely painted silos. Put your best decoys on the edges of your spread and in the landing hole. In other words, put your most realistic decoys in the places where the geese will see them first. Put your silos and your less realistic decoys back in your spread where they will "get lost in the crowd" and/or around your blinds/hides so they can break up your outline and your shadow. I wouldn't just pitch them aside, especially if you spent alot of time on them. It's cool to kill geese over something you made. Plus, you said they are on stakes that allow them to move. Movement is a BIG element that most people tend to overlook. That's why when you do invest in full bodies, get some that are on motion stakes.
If I was to venture a guess on what's wrong, I would say you aren't hid well enough.
Trust me, I know what it's like to have the itch to kill geese, but on a limited budget. You can pick up raffia grass at Wal-Mart for like $1.50 for a small bag. Use some small zip ties and attach a few bundles to your burlap. Cut some jute twine into small lengths and attach a few bundles of that to your burlap. You'll make kind of a ghillie blanket that you can pull up to your nose to cover up. Got some shell decoys? Put them over your feet. Remember to pile some natural veg on top too. Jerry rigging and coming up with new ways to fool birds is half the fun.
I'd say make getting a blind first on your list, then start building your spread with some full bodies on motion stakes. Keep an eye out for garage sales. You can also find good deals on some of these forums that have a classified section. I heard FA shells were to be had at a good price on ebay. I don't prefer shells, but you have to do what your pocket book allows you to do. Shells give you good motion when you put them on stakes, anyway.