YOU are not out much, the "Seller has a lot of negative, and neutral feed back. Pretty shakey dealer. If you purchase you can send it back, file a complaint with paypal or ebay. You might get something useful for you to get started with, probably will not last very long, but give you an idea if you want to hang.
My suggestion is to be sure not to hang it very far off the ground, and besure there is nothing under the hammock that will hurt you if you fall. I always move rocks and sticks out of the way just incase something fails. Also if you purchase it check it over carefully each time you use it.
ENO's go up to 400 pounds, both the single and double. They are kind of a known brand that does stand behind their product. You could also make your own hammock.
A guy gave me his REI tent that he lost the poles for, something like that can be used to make a tent, old parashoots give you gobs of nylon to work with.
Check the trees you are going to hang from carefully, you do not want them coming down.