Cost to List + Changes to Listing.Can range from $100-$400 for the exact same listing on the MLS.

While that may be true, take into account the total cost to refinance because it's not just rates that have to drop to make it make sense. 

Really I just want to learn how much things cost item-by-item.

I don't think there is any amount of savings that could justify the cost of a total tear down and rebuild.

This strategy allows you to spread out the lead removal costs a bit perhaps not having to remove Lead from two out of three units, and only removing it from the unit where you happen to accept a tenant that has children.  

With $50K, that would be a purchase price of about $250,000 not including closing costs and repairs.

Quote from @Bruce Cook: You should hire a professional property manager before you make a real mistake that costs you tens of thousands in losses.

I put 20% down and put a good amount towards the rehab cost.

The seller wants $500,000 down the operating cost on the property runabout $8500 and the seller wants a $9000 payment each month.

A current goal, would look more like “Save x amount for DP and closing costs for first property.”