There is one way to increase the height of your fence with minimal cost. Here is the process that you will need to take. 1) make sure that your existing posts (line&terminal) are in satisfactory condition. 2) Remove top rail and chain link fabric (save the top rail) 3) sleeve new posts over the existing ones, you will need to use a large diameter (ie. it you existing post is 1 5/8" then sleeve 2" over) you should only need them to be as long as the height you desire. 4) re-install top rail, you will need to purchase new fittings for the larger posts (loop caps, bands, and post caps) 5) Install new chain link fabric. 6) Have a glass of tea and enjoy.
The entire process should not take more than one day (average yard size).