(1) One good thing to do is find the right postal clerk who will pass through your bubble mailers, etc, at first class letter rate (about 70 cents if un-machinable), and not first class parcel rate (about $2). Postal clerks are notorious for having different standards.

(2) If you have a lot of inexpensive chips, a good idea for long-run savings is to use those corrugated self-sealing things to get your chips accepted at letter rate in a regular envelope. What's good about them is that they keep the thickness of the mail-piece no more than 1/4" (for letter rate) and provide some protection. Use only for inexpensive strong chips, like most casino chips. I don't use them, don't know best places to shop for them. (You could also use thin strong cardboard (like from a cereal box).)

Some terminology:
Defenda SpeedySeal Wrap - Self- Adhesive Corrugated Paper Rolls
(Sticky Corrugated Paper Rolls - Coldseal Adhesive Coating)...
Protection for a mass of products is provided by our rolls of Speedyseal Wrap….
Coldseal Cohesive Coating - Simply press the sticky corrugated side of the paper wrap against the other corrugated surface to which you wish it to bond, creating a fast & secure seal. The Wrap will not adhere to the product being wrapped.

Here is one place and pictures:
http://www.jpscorner.com/shipping-supplies.html

Robert