Hello,
You will be able to upgrade to CS-Cart 4.0.1 free of charge if you have an active upgrade subscription by the time this version is released (presumably June.)
CS-Cart Multi-Vendor is already purchasable on the year-long subscription basis: annual subscription costs $590. This subscription includes the right to use a single installation of CS-Cart Multi-Vendor and access to the software upgrades in the course of one year.
After CS-Cart 4 is released, newly purchased CS-Cart Ultimate license with one storefront will cost $395; each additional storefront license will cost $245.
Does this mean that you can only use the Multi-vendor for one year? If you don't renew your subscription then what happens?