You should be able to buy veneer cheaper than that. Most treadle cabinets are either going to be white oak or walnut. Here's an Ebay ad from Rockler.
http://www.ebay.com/itm/Flaky-Quarte...item3ce7179c6a
4ft x 3 ft would be enough to replace the top. If you need to replace more then you might have to buy 2 packs. Total would be around $50.
Admittedly that's only the wood. If you don't already have the supplies you're looking at more $ for glue, sandpaper, stain, varnish, etc.
Dang it, now you have me shopping veneer.
Rodney