I received e-mail from Thrunite saying that buying TN30 head, which is compatible with TN31 you can pick up MCC-4 for only 1$, its under “Optional accessories” selection in products description page:
http://www.thrunite-store.eu/thrunite-tn30-xm-l2-version-head-compatible-with-tn31/
Im not sure how good of a deal this is tho, but I thought to post it here in case someones interested.