Many thanks to everyone on the forum for their advice.
Although I was not able to get an expert to review the sword in person, I was able to have an appraiser look at the photos of the item to offer his opinion.
The appraiser estimated the value at a fraction of what the seller was asking for the sword and said the following:
i] "Although the photos make it appear reasonable that this may be authentic, the condition is very poor.[/i] I am responding with a viewpoint of someone with no attachment to this piece, so please take it as such. I know that you may have an emotional attachment to this type of items, but I would caution you.
Unless you really have to have this, I would make him a reasonable offer and leave it at that. As for locating items of interest for you: I would recommend setting up accounts with proxibid, liveauctioneers and invaluable. Once done, set up alerts for the items you are interested in. Then, you will receive notice when an auction gallery posts an item matching your alert. I would be patient. Things are always coming to market."[/
[/i]
Based on that advice and that of the members of the forum, I decided to pass on this item. To Mr. Albert's question, as near as I can tell from reviewing the papers of Clark's regiment they were issued at the most 100 to 150 swords because that is the total number of swords being issued to soldiers. Of course, many of those swords issued could have been returned to inventory after expeditions and the reissued, so the total number of Grenadier of Virgina swords in the unit could be considerably less.
It is frustrating to finally come across something that I believe is most likely the item I have been seeking for so long and not to make the purchase. However, while I think the odds are the item is genuine, it's certainly not a sure thing. With the appraiser providing an estimate for a sword in this condition at far below the asking price, it's just not the smart move to chance it at the price being asked.
Thanks to all the folks on the forum for talking me off the ledge before I made what probably would have been a foolish decision. Having only been collecting for a few years, that is the biggest thing I have had to learn -- to have the patience to wait for the right item at the right price instead of just jumping on the opportunity that is dangling right in front of me.