Cut the hardware off the ratchet straps. Tie a loop in one end. Voila - instant tree huggers. Did this for my kids hammocks. The straps were long enough to act as tree huggers and full suspension.
Spend the 25 on a blue walmart pad (<$10) and find a cheap 10x8 tarp at some place like Harbor Freight. If you have $ left over, get some braided mason line from a Home Depot to make guylines.
Cheap, not too heavy and will keep you out of the inclement weather.