fish, think he';s talking about a 5 point middle with 2 totals being sides.
(landing between 15-21 mentioned above)
bigbet, no generic answer to this question, will depend on the exact numbers involved. 3 to 9 is alot more valuable than 15-21.
With that said, I don't recommend buying back on half times to make this happen unless you have another good reason for it. Fezzik had an article on this a few days ago.