Is there an multicart/ebay/amazon/ clone that is made by an american company?
 

I need a multicart script that lets vendors sell their stuff on a site, but everything i look at is made by indians.
I bought one and the code and support are horrible. A $130 is costing me almost a grand in modifications just to get it right and its still not right

Is there one made by a reputable company?

Here's a bump to help you out, buddy

if believe presta shop has plugins for amazon and ebay that you can have your own store, the upload certain items to your ebay and amazon accounts.

Magento might be able to do that.

eBay owns Magento and it can be done.

I've used presta shop and there's plugins for that but they're not free last I checked.
The ebay one was only free for the UK.