How about this...
Run a monthly accessory poll (including pricing). End the poll on the last day of the month. Give the top three the group buy pricing for the following month as the "Monthly Special." If he's feeling generous, Tim could throw in a more obscure item as an additional monthly special (ie Burlwood Shift Knob, cargo net, etc).
The advantages of this system would seem to be multifold. First, more than one item would tend to balance the "newbies" and the "oldies" interests. Secondly, Tim could completely ignore the whole event until the 1st day of the month (other than filling all the orders). Thirdly, we'd all benefit from being able to see what's available. Heck, I only THINK I've got everything I need from Tim. I still watch for the monthly specials to see if some other cool thing might become a NECESSITY from Tim. I'm sure there are others, but I think I've made my point.
I purchased SEVERAL things from Tim, and only paid a non-discounted price once, and that was on one of his least expensive items. I used both discounting systems and I would hate to have to choose between them.
Heck, I'll volunteer to help set up the polling if needed.
Have a great weekend everyone!
jnbsdad