Cost-Plus pricing with multiple vendors

Hello--new to the forum and to NS--would love some help.

We're having trouble handling pricing in a way that's not labor-intensive.  Wondering if we're missing something or if there's an add-on 3rd party solution.

We are a distributor with multiple vendors (suppliers) for any given product.  Our web store offers approximately 10,000 items. 

We want a non-manual solution that will identify the lowest purchase price for an item across multiple vendors and then use a cost-plus formula to determine/set the online price (and base price) in NS.

While we're at it, we'd love to know about a pricing solution that helps manage large volumes of purchase price changes (that aren't as simple as X% increase across Y category) and item additions/discontinuations from suppliers.