So I go to RiteAid to buy the two LR44/GPA76 batteries for my newly found TI-30Xa calculator, and would you believe RiteAid wanted $4 a piece for those two batteries. That's insane.
Not only is the identifiers for watch batteries ridiculously unstandardized, the prices are outrageous. Searching more on Amazon, I found watch batteries selling for almost $10. I'm not going to pay $8 for batteries for a $15 (free) calculator.
After spending maybe half an hour on Amazon, I finally found a 10 pack of LR44 for $2.50, but here's the key, the shipping was only $4. There was lots of batteries for sale for less than $1, but had shipping ~$8. I'm not going to pay $8 so they can send me something the size of a dime.
So I don't understand why, but I just got the best deal overall for my 2 batteries by buying a pack of 10. So if anyone needs a LR44/GPA76/etc battery, just let me know!