Lot rents at $250 and running at a 40% expense ratio produces only $16k/year net  Is it worth it for the massive amount of work this place will require?

I own 30 properties in western PA that produce cash flow, but no appreciation. 

They are all in c class areas and produce very well.If you plan to enter the C class investment world, I would suggest that you have a plan to scale up.

Just ball parking on the numbers you gave, in which it appears that 11 units are producing the current income.

Long-term I'm hoping to build a portfolio of cash-flowing properties that produce enough income to live off of! 

My recommendation would be to get into the local REIA AZREIA.org they are one of the best in the country and you can learn tons and meet seem great contacts.I have looked at some of the 'flips' in scottsdale and in my opinion many of them are Subpar so if you produce a superior product than I would imagine that as long as you can find the right deal you will not have any problems.  

It produces 6% return.

Doing this, you *might* be able to find a few properties that will produce the cash flow you are looking for. - Option B is a little more farsighted, and a little less "analysis" based.

@Jeff Thompsonwhen you sell investment owned by the IRA - the gains are sheltered from taxes (because IRA is tax-deferred vehicle) and when IRA-owned investment produce income or cash-flow - it must flow into the IRA and also will be sheltered from taxes (unless the income is unrelated business taxable income). 

I am interested in learning how to either flip houses or invest in property to produce long-term income now, so that when I finish graduate school my wife and I can best invest our income early on.