Hi again.
No, there is no out-of-box integration with any CRM with the product (there are some RMS <> ERP integrations, but not 100% integration), so no integration with Microsoft Dynamics CRM also.
Well, to be honest completly, the cheepest integration will depend on many factors, like who is doing the integration, with what CRM product, what technology, etc., etc.,..., so you better do some good investigation on exactly what options you have, what products are out there, what you want to do with them.... I'm not saying it's going to be too expensive, but still ... If You want to use CRM for marketing purposes, there are other free pdoructs You can use (again not integrated with RMS), if you want to use it for customer loyalty (points, levels...) You may want to look at some of the existing 3rd party RMS add-ons (like Retail Hero for example), etc...
Regards, A.