I do not think that the stats "Speed in this session/minute/per hour" are very, very important (besides – okay – giving me an sometimes useful hint, motivating and telling me how great I am), but there seems to be a mistake (again):
"Speed in this session" is correct. "Speed per minute" does not have the right word number and not the right sum (here 0.12 EUR per word). "Speed per hour" has /roughly estimated) the right word number, but no the correct sum.
Anyone can reproduce this?
Sure, 65 Euros for 8 words would be a good deal...
Minutes and hours are rounded so the average numbers are okay. In your example 13.4 words value is rounded to 13 words. However, there is an issue indeed with the "Speed per minute" rate" as CafeTran resets the minutes counter after each hour. It shouldn't do so. To be fixed in the coming update.