An interesting question is "what is the value of an older back with no service attached?". The answer would be quite easy to compute - just subtract the dealer margin, and then divide the price of the the back by 2 again to account for age. Surprise - you get the LL "for sale" price of most older products.
Yep, that's what makes MF quite feasible for do-it-yourselfers and risktakers
. You need patience too though, if you desire a specific lens or back it might not be available on the second hand market right now. If you do get a lemon it can become costly and rather painful though, I'm quite a poster boy for that, but in the long term and in a large system you'll save a substantial amount of money by going second hand, so it's a good approach for amateurs.
I'd say it's not for professionals though, due to the risk and wait involved. For a pro I think the by far best way is to either go for the latest and greatest of MF, buying exactly what the local dealer recommends to you, and if that seems too expensive then not use MF at all. Otherwise I don't think MF can live up to the great service and support reputation. I do see quite many professionals actually dealing second hand too, I think they have backup covered in other ways than trusting dealer service though.
The are different "professional personalities", in all business. In my pro business, software development, there are many that outsource all their servers and development platforms, it costs a lot, but you get service and hopefully you don't need to spend any time yourself on the gear and just focus on development. Others, like my own company, buys lower cost standard gear, install and maintain everything by ourselves. Depending a bit on how you count you win or lose money on it (using high cost personnel to do "simple" tasks), but when owning your own business you generally don't count all the hours you work...
