This may or may not work for you at your post office, I have never had a problem myself. If I'm mailing inexpensive chips, here's what I do:

1) Place one or two chips in a #000 bubble mailer which I buy on eBay for approximately 25¢ apiece in bulk lots of 100.
2) Affix a 70¢ California Dogface Butterfly, Non-Machinable Surcharge stamp to the bubble mailer. I buy sheets of these stamps from the Post Office ahead of time so I can have the mailer ready to go before you drop it off.
3) When you mail your chip(s), drop the mailer in a drop box away from the post office or at least outside in the parking lot. When you take your mailer into the post office, the first think the counter clerk does is get out their little template with the slot to see how fat the mailer is and then they want to charge you over $3 to mail it. Dropping it off away from the post office circumvents the template.

One thing to consider is tracking is not available using this method so if you are mailing an expensive chip you might want to take it inside to the counter. Hope this helps!