As I understand you, the orders would go through the LLC prior to going to the abstractor for accounting purposes?  Yes, that would be a way to keep track of the orders for abstractors payment of using the LLC services. 

I assume collections would also remain in the hands of the abstractors and if there is a payment problem would the LLC get involved by either assisting the abstractor or refusing orders from the client?  Or would there be a threshold the client would have to cross, payment problems with 3 abstractors and ok with 20 others?

Again you would need a staff, office, computers, etc... to over see the assignments and the day to day operations of the LLC.  I was wondering what the initial outlay were you thinking about?  Yes the assignment charge might sustain the LLC, but you will need capital to get it up and running.  I know the capital would have to come from the membership, but how total capital are you talking about?

You are correct LLC's are taxed the way you described and that information would still have to be sent out to each LLC member at the end of the year for tax purposes.

On the pricing that is something the LLC will have to set.  Marketing companies usually don't determine price, they may be able to research price and get a going rate for East Coast, West Coast, Mid-West, etc... rural vs metro. They will dress up the product and/or service and present it in a favorable light to the client.

Keep talking, I'm listening

Jay