I'd like to add one more thing in response to you.
Amongst your confusion you pose the question why do paypal rules matter to me? Regardless of whether they matter to me or not is irrelevant since I never initiate any inquiry of PP rules. However, since everyone is so intent to continue this discussion of ethics (and now rules) I will contribute.
Paypal "gift" option is among many categories of payment all within the "personal" option. Along with "gift" there are alsO options for "payment advance", "living expense", "cash advance" and finally "other". According to the PP rules, which I've had no issues breaking for over 10 years, swapping, trading, selling, buying and reimbursing friends for knives and other gadgets can easily fall into the "other" category.
Now like many here, I am a hobbiest. I've not once got involved in knife collecting as a business. I have 2-3 very close local bladeforums friends, and happy to say I've made some great friends all across this country through BF. It is not uncommon at all that I have a friend I know is looking for a knife, and I'll buy it for them if I happen to see it pop up for sale. I'm not asking for finders fees, I'm not turning a profit, and I'm certainly not running a business. When I hand over that knife to my friend, and they ask to send me the money VIA paypal are you saying I should eat those fees? Are you saying that this scenario can not fall under the "personal", "other" category?
I'll just disclaim that if I've used the word "gift" in the past, so be it. I think we all realize we're talking about Paypal "personal".