All I can say from buying bikes on ebay, is that “local pickup only” hammers the prices down……. I picked up a BMX that would usually go for £200+ for £40 because of the awkward location.
If your selling kids items, its likely that the kind of people who will buy this may not be in a position to collect.
People simply won’t bid. Why sell on a national/global site like ebay, if you are rejecting any buyer over 20 miles away?
If they want to pay for a courier, who will pick up at your convenience, why deny yourself ££££?