If there is a washer nearby that is gravity draining to the sewer, this sink could be done right without a pump. To do this right, you would install a trap and tie the sink drain into the main drain where the washer is going, and vent to the stack above. Some tips for doing this the right way are at this link: http://doityourself.com/plumbing/plumbdrain.htm
Somehow, I dont think you are going to go to that effort, or cannot access the drain line. The work-around is not quite to code, but that doesn’t seem to be a problem for you here. You need a tail-piece and P-trap for the sink, and couple of extensions, angles and a Tee fitting for the washer drain riser. You want to install the drain fittings on the sink and see what elevation you have at the outlet of the P-trap. Cut the Washer drain riser just below that elevation and install the Tee. Now connect the sink into the new drain tee and tighten everything up. Lots cheaper than a pump, and it will get the job done. Since we are cobbling this together anyway, you can probably forego the trap on the sink, since there is already on the washer drain.
We call this a three trip job, because its going to take 3 trips to the hardware store to figure out all the connectors, reducers and parts needed to finish, but if you can figure out how to pump this thing somewhere, you can figure out a way to achive a gravity drain (preferably the right way). If all else fails, a bucket will work.
Plumber Tom is not going to be happy with my advice today. If he happens to live nearby, you should probably pay him to do this job right. You never know, a plumber might discount work on a bar if the working conditions are friendly.