Apt Unit Rehab Dollar Amount Formula?

[Eva Salas]

Hi, 

I'm  re-renting an apartment unit at $450 more than the previous long-term resident paid. It does need renovation. I could go crazy at HD/Lowes finding things that could be replaced. 

Some of the updates are discretionary and not absolutely necessary.  My question is, is there a formula others use when rehabbing units for incoming tenants? Such as, spend no more than what you will be paid back for in 1 year? In that case I would spend no more than $5400 ($450x12). 

 Yes, the unit could use that much improvement! However, I can get by without doing some things.  Examples of what it needs: new windows, hardwood floor refinishing, doors, tile kitchen floor, light and bathroom fixtures...

Any thoughts appreciated.