My local Walmart had polycro (window film) marked down. $5 for the window kit which has 2 pieces about 5 x 17.5 so you could easily get 6 groundsheets. Or if you wanted a very light albeit not very private tarp (see this thread) the 7 x 10 large door kit was only $4.50. Since it doesn’t stretch like LDPE, far less tape should be needed.
