Great suggestions. The value one I think needs to be current value. I’m ok if you bought something on sale for $30 when it’s normally $50. But if you got some grand cru Burgundy for $39.99 20 years ago and its valued now at $200, it belongs in the over $100 category.
Once I lock in a date and we have the group, I might narrow down the scope a little.
We can use Wine searcher’s lowest price, or maybe avg price? Winebid also has their “evaluations” but it is harder to reach each page, but I think we will still need to find a particular source for that value.
I know a lot of people on this site seem to use wine-searcher for valuations, but for higher end or back vintage stuff it’s usually way too high–auction values are the only true metric for those types. This is often highlighted when people list their stuff “10% below lowest price on wine-searcher” but the auction prices are 50% below… anyway, enough of a rant…
Wine-search is best for current vintage, large production stuff that is readily available. So yeah, feel free to use it if the bottle qualifies… and use best judgement otherwise. This is going to be a fun event and I can’t imagine anyone will be upset if your “cheap” bottle is $45 at current prices