Cheapest HP RPN, does have basic scientific functions.
20 October 2014
Summary: I'm an engineer who has used a HP RPN calculators for most of my life at this point, and can't stand to use a standard calculator. I have an HP-48sx (and a backup gx) but wanted something smaller, lighter, to carry around. This appears to be the cheapest RPN calculator HP sells currently. Even though it is targeted to business folks, it has the core trig functions, etc. (although some, like inverse trig, are down in menus, ew).
Summary: The calculator also works reasonably well as a scientific calculator having essentially the same functions as the original HP-35, though most requiring the shift key, which isn't as bad as it sounds. I did discover a bug, which I had not seen previously reported, which is more annoying than serious. While the STO MODE capability can be easily used to change most modes, it does nothing if a 12 digit number is supplied, as provided by RCL MODE.
I would recommend you spend just a little more money to get ...
7 September 2014
Summary: This calculator was very inexpensive, but it is very hard to use. I ordered enough for a small real estate class, and we all had difficulty getting the simplest TVM problems to work out. In fact, I am not yet convinced that there isn't some internal programming error in this unit. I would recommend you spend just a little more money to get a calculator that is easier to operate.
Summary: HP-30B Business Professional Calculator I use this calculator a lot at work. It's quick and accurate and you don't have to change to a function like you do on a computer. It's a calculator and that's its sole purpose. For business professionals and students, the versatile HP 30b Business Professional has an intuitive layout, high-speed processor and 2-line display for fast answers.
Summary: It's good enough for its purpose. I have a 17BII+ that I maintain in my suitcase and use for tests and for work, and this 30b is an extra that i just leave at the bank on top of my desk for a quick calculation and so far, no problems.
Seemed promising, but then I tried the depreciation function.
Stephen L. Martinez "enuance", Amazon
21 March 2014
Summary: I love that the layout and the menus were so much more intuitive than the TI BAII+. Also the feel and professional look of the calculator was a plus. However, I was thoroughly disappointing when I started to used the depreciation function. It seems that the calculator can only give correct answers in the Straight line mode. When I tried using the Sum of years digits mode of depreciation, every single one of the real book value results were incorrect.