I have paid 40 cents a square foot each for drywall hanging and finishing labor only, side work. 

I was wondering if anyone knows what the average cost per square foot for a full gut rehab?

Typically this will equate to a set reconstruction cost per square foot. 

Many like to use 10% of rent for that value, others at 185/month and still others 1 dollar per square foot per year.

Now, the only thing left is to put your foot on the gas!

The real answer to your question is take a look at the properties in your area that are selling for more than you believe your house is worth today and see if there are patters such as: square footage, price per square foot, bathroom tile, floor plans, paint colors, deferred maintenance, etc. and then see of those factors, which you can have any influence on with your current house and financial condition.

We're seeing costs right around $200 a square foot including all costs.

While increasing your property value, reducing carbon foot print, increasing cashflow, and make the rental property more appealing to high end consumers.It seems like a pretty solid plan to me, and I plan on implementing it when I get some rentals, can any landlords give me their opinions on this?

I then tore the house down and am building a 2,000 sq foot home that will cost me about 220k to build list price 650k in that area.. 220 plus 211 = 431k  cost of capital 19k in it 450k  sales costs 30k net profit 120k or so... will post pictures and numbers when done..

It's a "higher' end deal (will sell for $130/foot) targeting young well to-do professionals.