Need a really cheap CRM

I look at this list and see what I thought were low prices, but I thought "users" were admins. I expect to have thousands of sales people, maybe 10,000 even, paying perhaps a $10/month fee. And most of that fee needs to go to cover my management costs, not the costs of my CRM service.

http://blog.capterra.com/free-and-open-source-crm/

I guess I just don't get the pricing. Are salesmen users? If so, only this one works:

Even Really Simple Systems costs $8 per user.

I seriously think I need that open source option where all I need to do is host it. Sugar, the predecessor to SugarCRM. Please tell me about that one. And is it difficult to support it?

Can any of these help me?

http://www.softwareadvice.com/crm/visit-website/?url=customer-relationship-management-software&target=open%20source%20crm&ad_id=120106281186&matchtype=e&gclid=CJjgg8Xy7M4CFUEmhgodIGIG1Q

Thanks