What has been the most you ever paid for a calculator?

[pier4r]

100 € my first 50g in December 2010 (self gift)

The rest of the 50g (I have other 3) between 50 and 40 euro.

The ti and casio that have the advantage of being popular - and still a lot of people throw them away instead of selling/giving them away - costed all less than 25 €
(9860G, 9860GII, voyage 200, algebra fx 2.0, nspire the first without cas, ti89 [gift], ti 34 from 1987, sharp el 506w)

The prime app on android 25 €
The prime app on win 10 pro 15 € (although I ended up using the "free" virtual calculator as the prime app was not able to connect to the connectivity kit)

Best purchases so far in terms of ROI, in order or priority
- 50g. It let me discover a world, this forum and others.
- Prime app on android. Amazing little math library that runs on the android monsters so I am happy as I can squeeze some additional value from those. It is practically what people asking for basic wants as the language is really easy. Although I end up using the 50g practically for everything.
- sharp 506w. I love the little thing. It does a lot and I still discover things that it can do with a bit of creativity or patience.
- ti89 . It let me appreciate what is the difference of having a large dedicated community. There are so many awe inspiring solutions for it.
- 9860g . Not as usable as I expected (very clumsy for programming if one discards the C SDK), but it is a nice big brother for the 506w when the 506 reaches its limits. While I use the 50g for programs or automated number crunching, I use the 506w / 9860g for real time manual number crunching. For example quick stats, especially if I have to data entry the values in any case (there is no way to get a CSV or is it cumbersome for my setup at home). For example it has no real problems for data pairs. See http://www.hpmuseum.org/forum/thread-12205.html