Final damage visualization

The damage has to many nuances and takes to much work and time to calculate.
Coming from work and trying to play for 1 or 2 hours is fun in till i try to upgrade my gear as become a chore. DPS is not a damage increase indicator and should not be enabled in the trade interface, that already costed me some divines, no in game clear explanation or indication that a piece is and upgrade or not without buying and trying or spending 1h doing some mad calculation its not fun.
We need at least a way to try the items without buying for an easy way to compare old vs new damage.
This will kill the casual players for sure.