Well, I'm not do a free shipping. So, ebayer has to pay for that. FYI the cost depends on destination and origin but the price is around $15 maxxed for 3lbs via usps priority. Just put the weight and three dimensions on ebay and it will calculate the cost for buyer.
If it direct invoice. I will include the shipping fees in the shoe price (just think that you use money to pay for ebay fees to pay shipping). Well most of my shoes are list $350+ so that's ebay fees are always cover for shipping fees.
In the end. You got more money than to pay for fees and buyer have to pay less than it list on ebay/stockx/goat. So, its win-win.
I'm not a big seller so that works for me.