I gave my insurance company three itemized lists - all items with full list price (ebay price if out of production) - all items with "street" price (that is, Musicians Friend or ebay) - all items with "street" price and reasonable replacement price (not ebay). The highest was of course the first list with full price.
They (State Farm) were really cool about it. They were very concerned about ripping me off. But they said they could only give me 90% of value. So they gave me 90% of the full list price - which ended up higher than either of the other two. Then they said to keep a list of all receipts, and if it went over what they gave me, I could send them a bill and they would cover it. I actually came in (with the help of the guys here) a couple of hundred under.