The mistake you are making is it looks like you think you can use the number on the HUD website as your rent amount. 

It can affect estimated replacement cost and therefore the amount of coverage recommended/required.  

Whatever you buy you likely won’t keep it down the line as you better define your investment strategy, so my advice is to pick an asset that’s going to teach you the most in the quickest amount of time.

And for the record there is a HUGE difference in the amount of odor in a unit from 3rd hand smoke which is what carries in in your person when you smoke like clothes smell and breathe smell vs the smell you get when there’s actually smoking in the unit.

Should I charge her a prorated amount of the original rent or the increased month-to-month rent for January?

Also, the amount of damage was so expensive to repair that he simply could not afford to fix the more damaged units.

Be ready for a huge amount of information at your finger tips.

And is your purchase price target $150k, or is that the amount of equity you have to invest?

couple of bullet points to bring up:* she's on M2M* I told her on 12/7 of the new rent which would apply to a new Jan. 1 effective lease, this is when I got the "I'm moving out" message* Sent her the move-out letter on 12/11, with options for her to either be moved out by 12/31 (she's fully paid up for month of December) or by 1/11 (30 days from date of notice) and pay a pro-rated rent based on her CURRENT rent amount. her choice, either is fine with me.With all that said, I'd love to do as you mentioned and post a notice on her door. 

The amount saved can dwarf $6k.