Even though this should be clear, the numbers are not the important part here but moreso the mechanic I propose to change.
Since the R-Buff where her Q gets reduced by 50% during her Ult, most Vaynes started to max Silver Bolts instead since the Q CD is low enough.
This has lead to her dealing too much damage way too fast into the game for a late game scaling hypercarry. You also weren't able to just level Silver Bolts up before the Q-Buff since then you dealt a lot of damage yes but you were sitting there like a wannabe Kog'Maw with short range. Your Q cooldown was just too high to survive.
What I propose is to switch Silver Bolts with her Passive, it would look like this:
**Passive: Silver Bolts**
Vayne's basic attacks and Condemn apply a Silver Bolts stack for 3.5 seconds, up to 3 times. Attacking a new enemy removes all stacks from the previous target.
The third stack consumes them all to deal 4% - 14% (based on level) max HP bonus true damage and capped at 200 against monsters.
**W: Night Hunter**
Cost: 20 Mana
Cooldown: 16/14/12/10/8 (starts when the ability is completely finished)
Vayne gains 20 movementspeed for 8 seconds, this effect is tripled when walking towards enemy champions and quadrupled during **Final Hour** (also only when walking towards enemy champions)
This change will make it so her DPS once again comes online way later into the game compared to now, however she will also have new ways to survive the early game to get to that state and also have a certain "downtime" the enemy can capitalize on thus also increasing her counterplay (which is badly needed).
You can compare this change to Tristana, her efficiency is also heavily tied to levels (her passive)