I am installing a washing machine in the basement and the sewage drain pipe is at a height of 5 feet off the floor. From everything I have read, the standpipe should be above the height of the washer tub and it should be 2" in diameter.

Could I install the washer without having a external pump to pump the water up to the higher sewage line? I know that washing machines can pump the water up to various heights depending on the machine.

The specifications and installation manuals that I have read for the lower end Whirlpool and Maytag machines indicate that the standpipe height should be a minimum of 36" high and no more than 96" high. If this is the case, then could I set the standpipe height at about 96" high, with a 20" standpipe length which would then drain (downhill) into the sewer line at about 70". This would still allow the waste water to flow downhill into the sewer line.

Would there be any issues with syphoning or chance of sewer waste getting back into the washing machine?

Really confused here because I was told by the previous owner that he was told by a plumber that it would cost $2,000 for this installation due to the sewer pipe height.

Thanks in advance to any assistance.

As long as the manual for the specific washing machine allowes for the washer to pump up to 96 inches, you will be just fine with that height. Now, you mush have a minimum stand pipe length of 18 inches, and a max of 30" (in my area, although codes vary from area to area), and must be two inch in diameter. That being said, you need to also make sure you have a trap for the washer drain, and that trap must be vented correctly. The washer drain hose shall not be directly sealed to the stand pipe, just drops in, so if the sewer backs up, it will flow out of the standpipe and not into the washing machine. Hope this helps any who are concerned.