If you're seeing the awards available NOW and the difference is buying the minimum 2,500 miles from NW for $95 or joining White Tie for $149 (and also getting the club passes), I think that the later is the best value and you could regret waiting too long and seeing that you suddenly need 35,877 miles for that reward instead of just 877...
Did you check in CC for any amenity certs, etc?
peace,
~Ben~