Bulk fabric costs tend to start at around 100 yards, that's enough for a lot of boats.

You might look for nylon pack cloth instead of ballistic nylon. Years ago I made outdoor furniture commercially and used thousands of yards of that cloth, it's very durable and quite strong and you can usually get it in any color you like. It's coated on one side usually but not waterproof, still needs coated for kayaks.

Bill H.