Hey Joe,
agreed, estimating the costs for parts is not trivial. Yes, one approach would be to remove the price from the overview (as you already have done), but include it in the description.
I actually hoped that any of the Modulargrid admins would see this post in order to start a discussion about how to deal with the topic of DYI module pricing, since it's an unsolved issue as far as I know. On the other hand, I might be one of the very few who has a problem with imprecise quotation of prices. So please, accept my apologies if I offended you with my quite harsh words!
Keep up the good work!
MAB