Her ex pressure washed it and the inspector said because of that shingles are loose and needs to be replaced. 

I also am a CPA, I highly recommend working in Public Accounting to gain exposure to a multitude of tax scenarios before hanging out your own shingle.

You get a better job and longer shingle life out of tearing off the old shingles and applying new shingles over new felt.

Going to get on the roof tomorrow and bleach/scrub the black stains on the shingles.

If you have a shingle roof, your inspector should be able to give you a good idea of the condition. 

Again we told the developer we are for sale at $400+SF but we are proceeding with our development plans in the interim.Last week the property owner to the north contacted us (we had sent out a notice that we razing the existing structure and that the work might entail us needing limited access to their property to remove some asbestos shingles from our building).  

If there is old wood siding under the AC shingles, it is likely to be coated with lead-based paint, and that is also very highly regulated.

I've heard about people actually painting shingles with a certain kind of paint, although, Im not sure if it does a decent job or not.

I actually just mailed out a $5 rebate on 90 bundles of shingles for a $450 rebate.

I can get it fixed for $5k and you price it $8k because the $8k shingles and company "are better" or whatever and thus you think you can sell it for more.