Synchronizing external database to VM database?

[skullmonkey]

Hello,
In my company we have program for handling price, stock, images and other info about the product...
How can I convert that database to VM database so my stock and price are always synchronized? I need any solution possible.

I found service for that on http://www.shopping-cart-migration.com/provided-services but its too expensive service for small company.

Please point me to some direction.

Thanks,
S@