I have also been looking for routers on Ebay and found that it is important to include the 'cnc' bit in the search terms, if it isn't there then hundreds of normal router tables show up in the listed items.
The cheapest I have seen (buy it now for a large-ish machine) is 400 uk pounds for a table 2.5 mtrs by 1.5 mtrs, described as old but serviceable.
They seem to be a desireable item and anything with good linear bearings and ballscrews reaches a high price.