The biggest disappointments we see come across this site is people who are told for years from relatives that something is very valuable or have purchased something that they have heard is very valuable.
Most of the time it is...just not to the value that the bearer thinks. You have to also bear in mind that the cost of those items back when they were made/originally purchased...it cost alot (in relation to the economy, income) and items were viewed with more respect. The feeling of value and respect doesn't diminish over time on things that were worked hard for.
But a very clear reality is that not all items are valuable to everyone and to the market. However, considering that this item most likely cost around $18 tops when it was originally made....it has increased considerably if it sells for $90!
Now, as for Bigwull and a "real valuation". BIgwull is a rambunctious, knowledgeable, unpaid volunteer who gladly gives time and knowledge to help others learn about their items. He went above and beyond on this item as usual. AND as much as we might not like it, Ebay gives a general value (most of the time) that people are paying for items. If a store or auction is selling an item it will go for a little more but not a whole lot more! The occassional elusive item gets by for cheap, but if you look at the market as a whole...you get a "valuation".
If you are wanting a "true valuation" then you will need to take it to a professional for a HANDS ON evaluation of the item. It will cost $$. If you want an "insured value" you will have to do the same thing with a professional, HANDS ON, evaluation.