Are you using the PM boxes you get at the PO or did you order Regional A & B boxes from USPS.com? Regional boxes tend to cost less to ship and they're a bit larger than the PM flat-rate boxes. USPS will deliver the Regional boxes to your door and they cost nothing.

I use the regional rate when it is the cheapest, in fact I really like the regional rate alot, but anything east of Texas, the regular flat rate boxes become cheaper, kinda makes me wish I lived in the middle of the country, so shipping charges would be cheaper, then there is the occasional item that I can't fit in a flat rate box, I always try every option possible, in fact I offer to buyers several shipping options, parcel select, or priority mail usually. They hardly ever choose priority mail, but often times depending on the item, a regional rate box or flat rate box ends up being cheaper than the parcel select rate, so I send it that way and they feel they have been upgraded and it saves me money. I used to put flat rate as a shipping option, but changed to straight priority mail or parcel select calculated by weight and it works out pretty well for me. Sorry for the long response

Priority mail tracking by itself does not cover international shipments, the tracking stops when the package leaves the USA. If the item is less than 4 lbs. then go with USPS First Class, it is the least expensive and now has tracking when shipped using eBay shipping labels.

Actually there are several countries that you can get delivery confirmation of now through printing labels through ebay lables for International Priority Mail. I have now done it twice to the UK and once to Canada, the tracking is not very detailed but it tells you when it clears customs and when it is delivered. I feel more comfortable shipping international now that this feature has been added.

"New for January 2013, free electronic USPS Delivery Confirmation International offers scan events for customers using select software or online tools. E-USPS DELCON INTL is optionally provided for certain Priority Mail International Flat Rate Envelopes and Small Flat Rate Boxes to select destinations. It will be available first only to Canada."
http://about.usps.com/postal-bulletin/2012/pb22352/html/kit.htm

I have found that older credit cards from the 70's and earlier are collecitble if in good condition especially Amex and from what I researched, it is pefectly legal. I am guessing from the age of the card there is no risk of identiy theft.

Went to a local auction yesterday supposedly 7 lockers including managers own locker full of tools. only 6-7 people there, me and 1 other regular, and the rest first timers. First locker was the managers tool locker, lots of good stuff in there, minimum opening bid $2000, hence no one bid and we moved on, 2nd locker full of trash, looked like good stuff had been removed by tenant before deciding to stop paying, Newbie got it for $25. Next was a 5x10 with lots of boxes and tubs stacked neatly including a 42" LCD HDTV box, as well as what appeared to be a loveseat and some nice lamps and other decorative. I decide to go to $300 and see how I felt from there. Opening bid of $25, other regular bids, I bid $50, he goes $75, me $100, him $125, me $150, he drops out.  I scored it for $150. (Deets later). next locker was empty except for some dust, next one had just some broken furniture, other reg got it for $25. Last unit had old washer and dryer only, other reg got it for $25. Auction ended, The manager let me look closer at his tool locker after I cleaned out mine, I estimated in resell value there to be $2000-2500 in tools there, and he would not budge on his $2000 minimum, nor would he sell anything indivdually so I had to pass, even though I love tools, they sell really well, the profit margin just was not there. Well back to my unit, The TV was in the box, not only that but it was never opened brand new. Also found a almost brand new kitchenaid mixer, an ikea TV stand, and a ton of high end dishes and pots and pans(I think mostly wedding gifts). My wife is replacing alot of our personal dishes and cookware with items out of this unit as well as keeping for herself a bunch of other decorative items.(I have never seen her so anxious to help process a unit. The loveseat turned out to be a small sectional that my wife wants to keep even though she said she would never use a used couch(germaphobe). Anyway even with my wife keeping $300-$500 worth of merch, I will still pull out $500-$700 on this $150 unit. The best part is it only took 3-4 hours to process it all and only one box of personal items to return and only 1 box of garbage! Now if every unit could be like this one 

HI, just registered today, thought I would introduce myself. I have been attending storage auctions and bidding on units in my spare time for about a year now, so I am still relatively new. I find the shows interesting but unrealistic and they don't show the ugly side of the business - cleaning out the units and selling the stuff. Anywya I wanted to do this long before the shows even existed, but the wife was not up for it, until she saw the show on Netflix. So I guess I do have to say I started because of the show although I don't like to admit it. I look forward to sharing some of my experiences and hearing more of yours. Happy Hunting!