It all depends on what your goals are for the swim. My reference was for an athlete to achieve "peak performance." So it's a performance goal.
Your goal doesn't sound like you are terribly interested in performance since the "cost" seems to be the main driver.
The whole point of a high intensity approach is to minimize the amount of training stress for the given goal. In general, if you followed a traditional higher volume approach to achieve your goal of 1:08-1:18 pace, you could get to the same place with a higher intensity approach on 40-50% less volume.
I hope this helps,
Tim
http://www.magnoliamasters.com
http://www.snappingtortuga.com
http://www.swimeasyspeed.com
Your goal doesn't sound like you are terribly interested in performance since the "cost" seems to be the main driver.
The whole point of a high intensity approach is to minimize the amount of training stress for the given goal. In general, if you followed a traditional higher volume approach to achieve your goal of 1:08-1:18 pace, you could get to the same place with a higher intensity approach on 40-50% less volume.
I hope this helps,
Tim
http://www.magnoliamasters.com
http://www.snappingtortuga.com
http://www.swimeasyspeed.com