BTL offers some of the most affordable and high value geomembrane liners available on the market. The price of any particular liner depends on its particulars. A PVC lining may be the most affordable, however, it lacks the UV resistance and durability found in more reinforced options. The size of your project will also determine cost, a small backyard pond will not be as expensive as a several acre reservoir.
No matter your budget, there are a wide range of options when it comes to initial investment, and longterm maintanence costs. No project is too small, or too big, and the growing market of available products and new technology will only make this truer.