The TI-30s were not expensive by the early 80s, around ‘82 the newest ones had dropped the red LED for an LCD and they had gotten flat as opposed to the wedge shape of the one in the pic.Do you recall the price of the TI? I don't remember the 1973 model but it seems like it was $600. I may not be correct, just was a helluva lot of money at that time. The first time myself and a bunch of my friends got ahold of one we spent all afternoon in a bar in Austin Tx trying to stump it, checking every calculation on paper to "check" it. Did it until we killed the batteries.
The SRs were pricey in the mid 70s, but I don’t recall the $$. They were the first, but it wasn’t long before there were way cheaper models available, and they had longer battery life because they lost the LEDs for LCD displays.