Introduced in 1978 and discontinued in 1983 the HP 37E was one of HP’s lower end business calculators. It replaced their HP 22 and retailed for around $75.00. It was not programmable but did have quite a few pre-programmed functions available. And, it had Factorial and 1/x functions. It utilized RPN logic as well.
The HP 37E featured a one line LED display as well as fixed and scientific number formats. The batteries were rechargeable.
An HP 37E sold for $42.00 on 5-22-2011. It included the original box, manuals, power supply and leather case. It did have corrosion in the battery compartment and a couple cracks in the plastic near the screws at the bottom near the battery compartment.