You aren't printing your postage through a service. I use Stamps.Com and yes I pay a monthly fee but I have a business. I pay nothing for delivery confirmation as long as it ships 1ST Class or Priority. At the post office you have to pay something like 85¢ more for this service. You can also print postage via PayPal for no monthly fee and no fee for delivery confirmation either.

Try printing labels trough PayPal but you may have to have your customers pay via PayPal. I don't know 100% how PayPal labels work. I do know I used them a couple times to send out chips and it seems to work fairly easy. Just my opinion. I wouldn't continue to pay the outrageous fee at the window of the post office for delivery confirmation (tracking) when it is free elsewhere. At the USPS.COM site you still can't print 1st class postage, go figure.