Are you a millionaire? - No? - Then don't power up

Note: I'm addressing powering up mainly to increase vote value

Source

Powering up won't give you influence

Certain users have low 100s of thousands worth of SP, with a maximum vote value of  1-2 dollars.

There is almost certainly no way the resulting vote power conferred to you from the initial investment is worth it. Unless you value $1 more than a down payment on a large house, or a Lamborghini.

The opportunity cost of powering up

For a normal user who has earned $10-$1,000 on a post. 

I guarantee you that, you will be able to extract more utility and more money by liquidating those investments, than reinvesting in SP.

Several thousand dollars could suffice to set up a business that could make you financially free.

I know, because I've done it (I'm no millionaire, but make pretty good passive income). 

Even $10 can buy you beer. 

But it can't buy you anything of worth on Steemit.