yes ZM sell the extra sprues, i posted in another thread recently how to do this and roughly which ones you need.
i recently received what i ordered, with shipping to UK the extra prop, engine, wingspar, u/c sprues came to 5,400Yn (approx $48USD) with 3-day shipping of 4,100Yn (approx $36USD). Ordering is simple, just email Volks service at either their Japan or US address.
Depending on what you are trying to achieve (for example the kit already has more than one canopy option), i ordered the following.......
E runner x2 (900Yn)
ɪ runner x1 (1,200Yn)
J runner x1 (600Yn)
P runner x1 (600Yn)
Q runner x1 (600Yn)
T runner x1 (600Yn)