Max sold a NOS boxed red tip on eBay for over 100£
There's your guide
You put it on and two people bid it to 30£ another day 10 people bid it to 80£. That's how the bay goes
How much does it owe you?
Nothing wrong with making a profit on the bay but on here it's my opinion you should just cover your outlay, postage and fees.
I bought a lovely aristo jr. It was on the bay from an obvious TSR member, I asked him for a TSR mates rate price and he gave it to me cheap, he could have made a profit on the bay but got his money back from me. As I will do if or when I move it on.
IMO thats how BST should work
For what it's worth the red tip is a great razor