I have been investing for 10 yrs part time, have built up a decent portfolio of SFH, Duplexes, Fourplexes, Senior Living Complexes and a few Commercial Buildings...the returns are solid but my maintenance and repairs are eating at me - not only money wise but activity wise (calls, complaints, etc.)Up to this point, I typically hire out to local contractors (plumber and electrician) and do the light maintenance myself, when I can along with a few individuals who help with light painting, fixtures, etc.  

Double closing is an option for sure, but if your spread is <$10K the double closing costs will eat into your profits a bit.

If not likely a big increase is coming and unlike commercial NNN where tenants pay the taxes you will eat that cost with an apartment building.Look at if it is landlord paid utilities or not.

A roof, furnace, driveway eat up almost all of your gross income for a year, nevermind paying for taxes, insurance, debt, maintenance, etc..I wrote a blog post that might help you understand the numbers.... in fact, that's part of the title.  

That could increase your holding costs and eat into that profit as well.An old investor I used to work with would say "the juice ain't worth the squeeze" and for $120k you might as well do some much less risk SFR flips that have a much bigger pool of buyers and will easily sell in a month or less.

Every time I sell a home the commissions are eating up a big part of the total profit I want to buy a home doing my own contract directly with the seller.

What is eating up most of your budget?  

While same could be said about how people calculate Vacancy Factor and Maintenance Reserves, I notice that people struggle the most with Cap-Ex Reserves.This especially becomes a problem when folks rely primarily on their rental income to eat and live.

If you start to budget $2K (for round numbers) for a round-trip flight/car rental/hotel/etc. you can eat away (on a percentage basis) at the nest egg pretty quickly.  

In that case you have an alligator that eats your lunch.