TI's price war with Commodore went into high gear in 1983, and TI pulled out of the market in '84. So your early experiences with the TI-99/4A were probably a bit earlier than you remember.
I had a similar story -- my grandfather grabbed one for $50 at, IIRC, JC Penney and gave it to me for my 4th birthday in 1983. Got my start with TI-BASIC as a young kid, then GW-BASIC on an XT clone a few years later. Then came Scheme, Pascal, C, C++, Java, Python, PHP, JavaScript...
I had a similar story -- my grandfather grabbed one for $50 at, IIRC, JC Penney and gave it to me for my 4th birthday in 1983. Got my start with TI-BASIC as a young kid, then GW-BASIC on an XT clone a few years later. Then came Scheme, Pascal, C, C++, Java, Python, PHP, JavaScript...