As you well know Stock Sync offers different solutions for all merchants. However, these functions are not in the pricing module.
The first, which is the Update function, where the users can update their inventory is based on a monthly subscription plan. This monthly plan is based on the Limits.
Every plan has its own Limit, it is based on the variant(s), the number of update feed and schedule frequency.
For example, the Basic plan as above. This plan only has the limit of 4,000 variants in your store and provide 1 update product feed. And the schedule frequency limit is capped at 12 hours.
If a store has 10,000 variants and connecting to 3 suppliers (update feed) and needs to run the schedule every 6 hours. Then the store needs to subscribe to the Pro plan, which supports up to 10,000 variants, 3 update feeds and provides the min 6 hours schedule frequency.
Stock Sync Credit
The second, which is the Add/Remove Product function is not included in the monthly subscription plan. The Add/ Remove function falls under the Stock Sync credit.
Users need to top up their credit in order to Add products/Remove variants into their store. Currently, the cost is $0.01 or less for each product/variant.