Well, I'm one that bit the $500 dollar MagnaShade bullet. I must admit that this is the only item I've bought for the RV that I had a problem forking over this kind of money for. But, I have no access to a sewing machine capable of getting the job done.
Now that it's said and done, I have to admit it's a quality shade. We too are in Colorado and two days ago we had a 50mph wind shear event...the shade stayed put.
Those magnets ARE powerful! Make your own or buy one, be careful with those magnets...get 'em anywhere near each other and they'll pinch the fool out of you.