Wow, it seems like there are new Liner providers popping up all of the time.  I've checked out a few of them and have noticed a few things:

Many seem like this is a side business for them, and it probably is.  Their sites seem to be geared towards larger commercial purchases.  Some don't even have a way to purchase online, you have to call. The Backyard Ice Rink specific sites all want you to buy their whole "system."  I haven't figure out how to buy just the liner on these sites.  You would think that these sites would wise-up and realize that there are many people out there that would buy just parts of their "system." Most don't give free shipping, and because the liners are heavy, this really adds to the cost. There are a few sites selling 4 mil plastic as a liner.  You'd have to be awful careful with this stuff.  On the plus side, it would be lighter to work with and less to ship! I'm pretty convinced I'm going to try a new provider this year, as my old provider is way across...