Petsolutions, which has fairly competitive prices, offers EPDM liner at these rates:
[10' x 10' $69.99] [10' x 15' $114.99] [20' x 20' $279.99]
This does not include shipping which I would guess is very very high.
A LFS offers 10' x 15' at $172.50 or $1.15/sq ft
A roofing company offered it to me at 41 cents/sq ft. This is equivelent to $61.50 for the 10' x 15' size.
HOWEVER, the guy at the LFS said the roofing products contain chemicals added to prevent mildew on the roof. He said these chemicals would kill the fish. While I have established that the roofing material is 3x cheaper than the LFS variety I am still not certain as to its safety. Does anyone else have any firsthand experience with this? Would doing a few water changes prior to adding fish and plants help?