Been hanging for five years, about your size, in considerably less sometimes, with no problem. I would not worry about the weight issue at all. 2 layers of 1.9 is strong. Some high quality straps and buckles or whoopies with straps and you are good to go.
Just remember, never hang any farther up than you are willing to fall. I always think about that when I hang my hammock. I also spend a lot of time looking up for any potential hazards.
As far as cost, that is something you have to evaluate. Just think of the number of nights per year you will spend in it and the number of years you will have it, divide that into the cost and see if that is a number that is reasonable for a good night of rest and all the joys of hanging.
My guess is you will come to a conclusion that favors the $ spent.