Dale, I spent several years as a manager of an auto dealership after I retired from the Air Force, my son has run a transmission shop for near 32 years. Based on my experience with extended warrantys and knowledge of transmissions repair cost, I would say you came out on the good side of the deal. First off, over the period I worked in the business most ALL warrantys have some form of deductable, a hundred dollars sounds fair. (an extended warranty is nothing more than an INSURANCE policy on various things on the vehicle.) I don't know what tranmission rebuild goes for in your area, but here it averages about $1200. a good rebuild will go for approximately $600. (I recently seen a used stick shift transmission for a Dodge 3500 4x4 pickup go for $2800. plus labor for the exchange and new filter and fluid (28 quarts) and the guy that owned the truck was happy)
I won't debate the issue, but a torque converter is what causes the engine to lock up with the transmission, it can sometimes cause a hard shift, as said, most likely from low fluid, dirty filter, fluid, etc.