If a 2500' roll can be found, then by all means go that route. I have tried looking for long lengths in the past, with success at times, but most of the time having to settle for shorter lengths. I have wasted a lot of time looking for long lengths, so it is not an efficient way to get on with the job. The problem is that small direct-burial shielded signal cable is not often needed in such long runs. It would be luck to find a suitable piece.
Houston Wire and Cable might be a place to check for long rolls.