Priority mail boxes are free at the post office as are shipping labels etc. And if you use paypal and have money in an account you can print out prepaid shipping labels for priority mail...paid for with your paypal account with free delivery confirm.
Fabs rather than use air bags etc in shipping if you drink water in the half liter bottles as I do, I just let the bottles dry and put the cap on. Just as good as air bags and cost nothing
Stronger too for heavier items. Post office also has flat rate priority mail boxes that ship for 8.20 I think with as much weight as you can put in the boxes...up to 70 lbs. I shipped a guy a set of bullet moulds and 35 lbs of lead ingots in one box for 8.20. BTW the fees from ebay and paypal will add up to about 10%...but it is a great venue for some items... A little known "fact" about ebay.
60% of the items on ebay never sell...and about 60% of them never get a bid. In 10 yrs I have failed to sell less than 15 items...but I sell outdoor items ya know.!!