The only benefit you get form lurker teir, is the full game when its released. Licker teir gets to play the current newest build a few weeks earlier then public.
Other words, no major benefit.
I should probably have rephrased that.
Besides if you already gonna get the full game on release with the Lurker teir, why ask for a buying price, if you going to get it as part of your teir?
Unless you under the other teirs, or just waiting for the game without supporting. Then i can understand the question.