I had almost the exact experience with iFixRobot.com

12/12/2015
My Roomba 4110 wouldn't charge and so wanted to send it to iFixRobot.com. They said the rough estimate for the repair would be an average of around $75 plus shipping.
12/13/2015
I said OK and shipped my Roomba along with the dock, charger and a new battery, which at that time had full charge. Shipping cost me $19.99
01/03/2016
iFixRobot.com received my Roomba and promised me that the diagnostics would be completed in 21 days.
01/12/2016
The diagnostics for Roomba 4110 was completed. I had to pay a total of $152.92 for the following:
Charging Circuit Repair $79.95
Clean and Lubricate Main Brush Gear System $29.99
Cleaning of Sensors and Interior of Chassis $19.99
Shipping, Handling, Discounts & Taxes $22.99
02/01/2016
In-spite of making the payment on 01/12/2016, they could not find my paper work. After reminding them several times and after waiting for three weeks, they let me know that the repair was completed and that my original battery had died, making me buy another battery for $39.99
02/08/2016
I finally got confirmation that the repair work was completed and the Roomba was shipped back through FedEx.

After waiting for more than two months and shelling out nearly $215 I got my Roomba back with both the old and the new batteries. Of course they charged me $1.25 for sending the old battery. Altogether although they did a good job on repairing my Roomba, I must say that I spent more than the original cost, which was $139.99 and had to wait 2 months. I would not recommend iFixRobot.com to anyone.