Also, keep in mind that you should have enough profit (NOI minus principal and interest) to be able to realize a reasonable rate of return and still be able to set aside some money for capital expenditures - for example, money for new roofing, paving repairs for drives and parking areas, etc.In the end, you have to get to the other side of analysis though.

You could consider REITS, Private Placement Deals, Hard Money Lending, Syndications, etc. and invest passively, or continue acquiring hard assets that come with heavier time expenditures.  

A thorough inspection is crucial and understand the difference between maintenance and bigger capital expenditures (capex) that you will need to save for. 

What you would normally want to do is establish your own escrow account for Repairs/Maintenance, as well as Capital Expenditures for your rental.  

I know labor costs are cheaper in the south than what they are where I am at in the NW.... see what they charge on average per sq/foot to build.A couple positive aspects to new builds that are often over looked are very low capital expenditures for a 10-15 year time period after the build.

2) Balancing Upgrades/Capital Expenditures (CapEx) Against Over-Investment:This is indeed a delicate balance.

From what I've gathered the properties will not begin to cash flow significantly better, you are in a market that cannot easily absorb unexpected capital expenditures (greater risk to you in the future) and the principal paydown is pretty meaningless for a while.

My initial criteria is to look for newer built houses to minimize maintenance and upfront cap expenditure on major items like HVAC, Roof, Foundation etc..

Where I live in Lake Tahoe, Nevada there are HOA associations have been poorly run, multiple insurance claims from snow damage, and as a result are increasing fees to cover the low fees of the past and capital expenditures that have been put off for years. 

Appraisals for storage facilities are not always common in smaller markets5.Develop a detailed business plan, including a marketing strategy, capital expenditure budget, and growth projections.