Thanks for the info, I can buy a used sp3 for about 450 in great shape on ebay. If I knew I could get a sp4 maybe. I was looking for someone that must do a good job replacing the battery for a reasonable cost. . May try it myself. All of the people with sp3 battery dead issues really points to defective batterys in the sp3, something Microsoft has not addressed. I kept my sp3 on a charger most of it's life to extend the battery life since I knew it was not easily serviced. My premature death after 2 years really confirms for me the defective nature of the battery.
Since these are not waterproof, the reason they sealed up and stopped having removable batteries on cell phones these days, I fail to see why the designers of the surface pro's haven't put some screws in the back for battery or fan replacement.