For those interested in how XP works or whether or not to pursue level 100, hopefully this will help. I found a set of equations that closely resemble, if not exactly predict, the experience curve for murder mystery. I am not level 100 yet, so this could contain mistakes. Feel free to correct this if there are any mistakes.
To go from level 1 to level 2 requires 100 XP.
To go from level 2 to level 3 requires 200 XP.
To go from level 3 to level 4 requires 300 XP.
Going from level 81 to level 82 requires 8100 XP, which still follows the pattern.
Going from level 82 to level 83, however, only requires 8100 XP.
I am currently level 83, so I don’t know for sure what happens next, but using the level 100 XP value, the average value per level after 82 works out to be exactly 8100 XP, so assuming that the XP requirement does not decrease, the pattern of 8100 XP per level at high levels should hold.
In other words, the amount of XP required to go up a level is 100 XP times the player’s current level, until it reaches a constant rate of 8100 XP per level at levels a current level of 81 and above.
Of course, it might be useful as well, if not more useful, to look at the cumulative XP requirement, since that number is what shows up in the statistics in the murder mystery lobby.
This can be modeled by the functions:
Total XP = 50(Level)^2-50(Level), which is valid only for levels 1-82.
The rest of the cumulative XP requirement can be modeled by the function:
Total XP = 8100(Level) - 332100, which should be valid only from levels 82-100.
According to these models, level 25 requires 30,000 XP, level 50 requires 122,500 XP, level 75 requires 277500 XP, and level 100 requires 477,900 XP.
I hope this helps.