Largest Price increase you have seen ?

[Durian Fiend]

How does voting different cause Young Bros charge lower prices?

Ask germans who voted for Adolph Hitler.

How much of a difference it can make...

Right.  Initiating a huge military buildup to prosecute a war during a depression certainly bump started the Nazi economy.   But you digress!  This is not relevant to the question asked. 

The current inflation we're seeing is a worldwide phenomenon with practically no relationship to politics. Only partisan whiners with axes to grind play that tune.