For those posting blu-rays be aware postage rates went up effective today. It now costs $1-40 (up from $1-20) for large letter rate which is the cheapest method of sending blu's. Be aware also if you send your AUS/ UK blu's in a bubble envelope you have a small (less than 1% chance in my experience) of copping a $1-50 fine plus the difference ($5-80) between the new parcel rate of $7-20 & $1-40.
You'd have to be pretty unlucky, I sell hundreds of blu's a year & very rarely cop a fine, but when I do it's usually 2 or 3 at a time, when they have their sting operations targeting letters that are over 20mm in thickness, bloody zealots.
Aus/UK cases are 14mm alone!
Yet another reason to buy US (12mm cases), at least I can resell them without worrying about copping a postal fine!