I bought a Texas Instruments SR -10 for $30.00 in about 1976. I crowed at the time that I had beaten the system because there was no possible way they could ever get much cheaper than that. A year later it shot craps while it was still under warranty. All that I had to do was mail it back to Dallas and they'd ship me a brand new one. A new, more compact calculator that would do all the same functions cost less than the postage.