If your adding it onto the same wall as the washer , yes it is possible and the cost should not be that high. Get a plumber in there and go for it.

Thanks! Yes, the sink would be on the same side of the wall as the washer.

As another poster noted, adding a sink should be very easy, as long as it's on the same wall as the washer. We're in the middle of a remodel. We asked our contractor to rough in a water and drain line next to the washer. All he had to do was to tap into the existing lines (both drain and water supply). I'd say it took no more than an hour to do the work.

It really depends upon how old the house is and what is there now.

years ago a laundry standpipe was a 1-1/2" line..Now the code requires the laundry standpipe to be a 2" line.

If you have a 2" line you could add a sink easily but if you have an older home with a 1-1/2" line the line is already maxed out at 3DFU's(drainage fixture units) so you cannot add any additional load..If its a 2" line that is good for up to 6DFU's. A washing machine is rated at 3DFU's and a laundry sink is rated at 3DFU's so they could be combined on a 2" line.

I'd love to add a laundry sink in my place and may well do, using the existing connections there, but the stupid builders made no allowance for it, room-wise - I may have to try and find an ultraslim one, or, it's occured to me, if I buy a stainless one, I might be able to get it cut and shut (welded) at a stainless fabrication place - I might be able to shoehorn one 8-10 inches front to back...