Fixed sell/buy bugs

Added additional prevention, fixed multiplying and error in logic when
buying or selling.
Revert "Fixed sell/buy bugs"

This reverts commit 42ab9808b9097a60b0a7ca37a2f3ba0ecff31ab5.
Trading Window Bug Fixes

Fixed if statements for trading and wrong adding of resources. Used
player array to store last price values.
Added temp values for new game for Player array.