What’s the most cost effective upgrading strategies that can increase rents?

Electrical upgrades and fixing various plumbing issues, and making sure that the HVAC system is not only working but working well.  

Or if you want to upgrade from 2-prong to 3-prong outlets (which also reduces fire hazards, and also makes your life more convenient if you live there) that requires re-wiring the circuit.3.

@Roy Mitle I suggest upgrading your team.

I also repaired some minor things to the property and plan to do at least 1 upgrade a year, even if it is small.

I am new to Bigger Pockets but am enjoying the forum and will be upgrading my membership soon!

Totally worth the upgrade. 

Price is approximately $90k but I would offer less in order to allow for the upgrades I plan to put in (approx. 20k for kitchen and flooring).

The current rented unit is only for $825/month but I should be able to bring it up to market around $1000-$1100/month and possibly up to $1200/month per unit when I move out once I make some upgrades which I plan to do as I live there.

This is from what they say a turn key fully rented 4 family with several upgrades.