"Energy per second" improvement shows the same cost for x1 and x10 (but do change color of the digits when not affordable), although in fact everything is in order, it is the display problem. ("Per AutoClick" and "Multiplier" seems OK).
Edit: it get fixed now that x10 cost more than 1 mil.
Edit 2: On the sword for 50 K it was written “Coming soon”, but this turned out to be a lie: the money was spent, the attack increased.