It sounds like your confidence was shaken by attempting to save money on a cheap product! Understandably, you are worried about what consequential damage you caused by installing an inferior starter, but that shouldn't shake you up when replacing with a proven product, even if it does cost more. I guess my philosophy is different, but I dismiss just about anything that is the lowest price.
BTW, I agree with MS about warranties. I've never bought anything based on a warranty and I never even pay attention to what it is, much less compare it with others. I figure that if I need a warranty, there has to be something wrong! Why would you care if the starter has a 6-month or 12-month warranty? If doesn't last 20 years, why would you want the damn thing?!
What I really hate is when the seller wants you to buy an extended warranty for anything. That seems to happen at the car dealerships all the time now. I'm sick of making an agreement on the price of a car and then when you get to the finance department, they want to sell you extended warranties. The last time around, I spent several hours haggling the price for a new car and when I finally agreed and was ushered into the finance guy to sign all the papers, I told him "if you even try to sell me an extended warranty, I'm going to walk out". Sure enough, he started to tell me why I should buy an extended warranty. I had to go to a different dealer to buy the car.