For the management of Third Party products also known as Drop shipping with a combined Retail Express and THQ connected ecommerce store. 
This is the preferred approach from our perspective. We have a special option / module available to help for a small additional charge with more advanced configurations with a large number of products.
 
  1. All orders go through to REX including all payments – Nothing gets “left behind”
  2. With our additional option All Third Party line items will be aggregated to a single Product code for Marketplace and this will be combined. You can call this anything you like “See Other invoice”
  3. Payment will be in full with any coupons or other changes applied. Any discounting coupons will effect the products as it does now, the discount will get applied as it needs to and may not apply tot eh products you expected depending upon your testing. 
  4. Shipping similarly will go through, as it does now, to Retail Express. This may need adjustments on your eCommerce store. 
  5. If you mark the item in Retail Express as "Prevent Disabling" then it will not do stock Management
  6. The sales and accounting will all work out but you would place the Third Party product like a drop shipping CONTRA account. This will be a subaccount from a Xero perspective.
  7. Refunds and cancellations need to also refund the  Third Party components.
  8. All  Third Party customers will be in the REX client list as well filling out the CRM story