Thank you very much for the link. There is Tamiya distributor at Czech Republic as well, but I hate to use their services. There is not very much TRF cars at Czech Rep. (I know about 4 buggies only) so they do not have anything on stock for them. Therefore they must order it from USA/Japan the same way as I would done it. Except there is one more shipping price included (from distributor to me), one more profit (I understand that they can not sell it to me without any), one more time delay (they order only once in a week, from Japan probably once a month), I think you got the point.
You are right there is always ebay, amainhobbies and other sites, but try to google 13700123 pulleys or 16248001 belt. Ebay do not know it yet, and what is even worse, Google will find nothing as well!!
I wondered if you guys can guess if these new spare parts will be available later, or if it will be just this special order thing forever. I'm in this only for 3 years, but perhaps you experienced similar situation with TRF products already, for example with common spare parts when new model comes out.
If the common experience is that sooner or later special order parts will be available at hobby shops and ebay, then I will risk the purchase and pray. But if special order parts mostly keeps forever being only special order items, then I'm afraid I will have to give up this beautiful upgrade