We also had a roof leak on the back patio.  

Is PEX the same thing as pvc; if so, I thought we couldn't mix copper with plastic? 

If the seller accepts the offer one of the things on my list to figure out is if the screened in back patio and backyard shed/1 car garage (that is built only 1-2 feet away from the neighboring fence-line is permitted or not.

If my buyers see pre-formed plastic on the floor they assume the entire place is junk and pass.

The condition of the house is pretty bad, ceilings are really low (i am 5'10), floor seems uneven,  entire house needs new flooring, new bathroom, kitchen, patio deck is warped.

Building constructed in 1980Present loan value appx $77k on a 15 yr note with 3.375% interestP&I pmt is appx $602NOI 2014 was $11489NOI 2013 was $5142      (spent around $4k on updates/remodeling)Appx $27k by my calculations of capital improvements needed in the next 5-10 years to increase the value of the property, properly maintain it, and keep it functionally up to date in order to attract higher quality tenants (located in a b grade area) (I'd rather have more invested to have higher quality tenants - have my own reasons for this line of thinking - willing to sacrifice a bit of profit to have good people)- Redo Kitchens- replace doors and all base trim/casing (more for my taste and would help the place rent out even quicker)- 2 escape windows installed for basement bedrooms- Concrete work needed on patios and near front of the house -- need to be done in the next yearProperty based on comps in the immediate area and a tight supply of decent duplexes here is $175-210k or so.  

I am using private money to fund the deal and would repay once the refinance portion is in place.2 Bed/1 BathOffered: $21,000 all cash, no inspection contingencyClosing Costs: $1,500Taxes Current Year: $1,800Needed rehabs(Estimated): - Fix grade issue $300- Demo and remove patio $500- Demo and remove moldy drywall in basement $150- Repair basement cracks/seal/paint $500- Dehumidifier $300- Paint interior $300- Paint Exterior $200- Add/repair downspouts $500- Replace boiler $3,000- Replace siding on carport $400- MISC Electrical $350- MISC/Oversights $1,000TOTAL Rehabs: $7,500ALL IN TOTAL: $31,800Comparables in the area are around 45k-48k on average.

(C) Buy those adjustable plastic grids from the big box stores and cut them to size and insert those green filter into them? 

We have to remove the cover, drape plastic underneath the unit to guide the cleaning solution and rinse water into a trash bin.

My rental has a few leaks from a poorly done flip at the hose bib on an enclosed patio and under the sink from the spray hose and garbage disposal.