I'm currently practicing dental hygiene part-time (2 days each week), and while I LOVE what I do, the physical strain of my career has begun to take it's toll after 14+ years. 

@Robert Whitelaw   generally speaking I agree with the buy hold will win the day.. but its just cannot be a blanket statementthere was  a very big apartment owner here in PDX that rolled up all his units  and cashed in 20 million in equity.. went to vegas in 05 on a massive 1031... bought 100 million in multi there.vacancy rates as you know on fully leveraged multi  in excess of about 10 to 15% put huge strains on those and much more than that you have to feed them.vacancies in 08 in vegas hit 10 to 40%  he LOST THEM ALL.... had he just held pat on his vanilla PDX he would be fine and our stuff here has sky rocketed  must like a little brother to silicon valley real estate.. 

I'm looking at a multi detached home and it looks like the foundation has shifted on one side of the house causing back porch, part of the kitchen, and door jamb to shift about 3 inches down, a hole in the wall in an upstairs bedroom, mold in the basement, and strain on the basement wal-out awning.

Neither of which pay their share of the utilities putting the strain on the other kids. 

I had to present to the historical society my plans to replace the windows with new, triple pane, vinyl windows.  

Is it energy efficient with double pane glass? 

The ROI (cost of new windows vs. utility savings) can take a very long time if the windows are in good condition, but just single pane...

The empty building at a good price allowed us to take our time and use our cash flow from the other buildings to fully renovate the building, put it back in the rental pool and get rid of one more strain on the neighborhood.

We found a $1200 Andersen dual pane, custom order, sliding glass door for $140 on OfferUp.

There are hundreds of strains of mold, and without having it tested, you don't know what you are dealing with.