J.L.
I think for me, it depended on the age of my baby. When she was a newborn (she was a preemie) she did not take to similac very well, it constipated her. Similac is the same at Parent's Choice, and Kirkland brands. So I had to give her enfamil (plus it was a high calorie formula I was told to give her). Enfamil did not constipate her and all was well. As she got older (around 4-6 months when she regularly ate stage 1 foods and rice cereal), I switched to Kirkland/Parent's Choice/Up&Up (target's brand). She did fine on it. I think her little system was regulated out and she was able to handle all kinds at that point. I can tell you from experience, if I opened a can of Target/Wal-mart/Costco brand and set them in front of you, you would not be able to tell the difference. Those 3 brands are exactly the same, even the consistency of the powder. Look for coupons too! Have fun!
I wanted to add, you don't sound cheap! Saving a buck here or there really adds up! =)