Not sure, if you know that, but many planes and other objects for Pacific Fighters, Manchuria, Pe-2 and 46 titles were made by a freelance 3rd party modelers. They were hired and coordinated by Ilya Shevchenko.
He had more or less standard pricing for the job, which was something like 1K USD per external aircraft model (complete with LODs, damage, textures, etc), 1K USD per single seat cockpit (+500 USD for each additional workplace in the same cockpit). So, basically, single-seat fighter cost him around 2K USD, paid to a freelancers. However, due to various reasons, 3rd party modelers didn't and couldn't do all the job, required to complete the model to the level, where it was suitable for the game engine export. The export itself was also beyond their abilities at the time. So, part of the work (to make the flyable plane model for the game) was done by 1C:MG full-time workers. Which means, actually it cost even more.
Also, the Pe-8 bomber was built by a 3rd party modeler for a donations, collected by IL-2 community. So, this idea isn't new, actually.
