Watching pipes on e-bay will give you an idea of what their value is on the open market. Also, you do searches for estate pipes of the same make and era.
As for the Orsini, from what I know, you got a decent price for the pipe.
Ultimately it comes down to this. Do you think you got a fair price for the value of the smoking experience you are getting from the pipe.
For example, I have yet to have a Dunhill that I thought was worth $50, much less the $300+ pricetag on them. Thankfully, I never bought one, but they were all estate pipes given to me. And others thing Dunhills are the cat's meow - whatever. Therefore, if you'd have said you paid $300 for a new Dunhill, I'd have said you were ripped off.
To sum this all up - you need to satisfy your own tastes and base your analysis for value upon that. It is kind of like your tobacco and cigars. If you like what you are smoking, and really enjoying it, who cares what anybody else thinks. If it is in your price range and makes you happy, then it is a good value.
That's my
Peace of the Lord be with you.