As a 12-year old child, so in 1979, I bought my TI-57 in 1979 by mail order from the La Redoute catalogue. Next to it were the ti-58c and 59 in front of which I drooled, but I didn't have enough money for these beauties.  Price : ¥ 260 (1979)
What a pleasure to program despite this famous limit of 50 program steps which was a real challenge.
I used this machine a lot, its main issues were volatile memory and battery life. I only learned much later that I could have put a 9 volt battery in it.
I kept it throughout my college period before buying the PB-100 in 1983, its basic and soon its peripherals.