I will second what GBBUDD said about Justliners. I had an order this Spring for two liners and two underlayments. Ordering online and delivery was prompt. They make it clear to you about being prepared about the delivery and getting off the truck, its a private delivery service so no guarantee of a lift gate. My order was about 450lbs, my little kubota with pallet forks was just barely able to get it off. Of course if you have a smaller liner not as big an issue.
Cost is definitely a concern but like prior comments you do want quality for something so important to the pond. Reality is that it is a niche product so these companies cannot put them on sale very often, they just do not have the volume of sales to do that.
Same thing with ordering a pump you can save money upfront going with a submersible but they do not last as long as an external pump and cost more to run. Again thanks to GBBUDD on pointing that out, basically he is good at spending other people's money, lol, but the advice is spot on.
While those items are pricey I look at the fact I am saving on labor by doing it myself plus I am using stone from my yard which is a big savings, it all balances out in the end.
