Not at all, it is the most practical way to ship USPS temporarily for items weighing more than 13 ounces, but UPS and FedEx ground services are still available at discount through the ebay label printer, you can easily arrange for pickup by either carrier right from your doorstep.
If you insist on using USPS parcel post, now called parcel select you have two choices until late March, (1) take the package to the post office and buy the postage there or (2) subscribe to a label service that charges a small monthly fee like stamps.com or pitneybowles.com. For whatever the reason USPS will not allow anyone giving away the service these companies charge for as eBay does to begin offering service for sixty days after the new parcel select program began last Sunday.
All of this info has been repeatedly given to you in the daily ebay announcements, perhaps if you start reading them you will be able to save more money and provide better service to your customers in the future.
Wish my fingers would pay closer attention to what I spell correctly.