Much like saddles and stems, many road forks show up on ebay after very little use, because they were unsuitable for the original purchaser, e.g. the wrong size after cutting too short by mistake. If you can locate such a "take-off" fork that is the right size for your, you should be able to do very well. Sure you don't want an old, beat up used fork.

The entire line of Ritchey forks is very good value. Their mid-range fork, the Pro is really excellent. You should be able to get a bit better price on the lower Comp model. The top-of-the-line WCS isn't necessary and can be pricey. But if you find one at a good price, that would be a really good deal. Just be sure to match your crown race diameter, your fork rake, and the steerer tube length you need.