Wife sells on ebay constantly. She's a Dr, not a stay at home mom, little free time, and certainly makes more than me!

USPS picks up for free. USPS delivers Priority Mail boxes/envelops for free (boxes also free). Print a shipping label from ebay for free (and get a rate cheaper than you would if you buy postage at the post office)

We havent been to the post office in years

You are going to shoot yourself in the foot if you start charging $5 more on shipping vs competitors on ebay.