Have you considered using a specialty insurance company, rather than your homeowner's policy to insure your chip collection?
Take a look at Collectibles Insurance Services at:
http://www.collectinsure.com/

I don't personally have insurance through them (nor am I associated with them in any way), but other chip collectors have used this company and have recommended it.

According to a "Myths & Facts" page on the website, an appraisal is not necessary. YOU provide the values (and your cost of insurance is related to this value, I assume). See their Myth #3, below:

I would advise you to prepare a list of your chips and photograph them (or scan them) so you have a record of the collection, then store a CD copy of the list & photos in a safe, off-site place, like a safe deposit box, or mail a copy to a relative in another location.

You can determine values by consulting The Chip Rack (12th edition) for Nevada chips, and/or The U.S. Casino Chip Price Guide (4th edition). Be aware that realistic values have decreased in recent months vs. the values in these 2 guides, due to the current recession. But these are a starting point. If you have chips not covered in these 2 guides, there are other references. If you need help on additional info sources, I'll try to suggest other ideas if you send me an email.

Good luck.