World Coin Price Guide

As far as I'm aware, NGC is about as updated as an online world coin price guide gets.

When NumisMaster was launched back in 2006, they said they'd update the prices more frequently than their once-a-year book releases did. Five years on, I'm not sure if they've kept that promise - you need to pay subscriptions to NumisMaster to see prices, and I've never done so.

As I understood it, NGC's WCPG was taking their pricing data from NumisMaster, but likewise I don't know if it's constantly receiving updates for the data or if it was a one-off data grab.

There are other "price guides" out there that may be of some use; WorldCoinGallery uses Krause book data and I don't know how often the prices get updated there; probably less often than the books themselves, I suspect. Sites like CurrencyDebasement only focus on bullion and face value (which can be updated regularly thanks to bullion trading and exchange rate websites), not collector value, but can give some indication of what the collector premium might be doing.

For pricier coins that only occasionally come onto the market, an auction collation database like CoinArchives might be more reliable. CoinArchives used to be excellent, but you now have to pay $600 to access the full database, so I can;t heartily recommend it anymore.