I've recently valued my coin collection using the 2024 Red Book and these four online price lists: NumisMedia, NGC, USA Coin Book, and PCGS. I found the average value of the collection using these five price lists, and then figured the percent each entity had compared to that average. Here are the results: Red Book 101% of average NumisMedia 84% of average NGC 97% of average USA Coin Book 109% of average PCGS 109% of average In other words, PCGS and USA Coin Book gave the highest prices, NumisMedia the lowest.
All such price lists are just guides. Some may be close, others higher or lower. So many things go into valuing these types of items.
I use a number of price lists and such, but I have always considered NumisMedia to reflect the average price for a coin that has NOT been slabbed. I also think they tend to go with the most common variety possible. Just for example, look at their prices for 1861-o Seated Halves, and then find the difference certain issues can be. I do find them useful though. One thing that often surprises me is how close the lowest price on the CDN correlates with same price on Numismedia when you do the math to find out the price of split grades such as VF-30, or Ef-45.
Value is also in the eye of the beholder. You won't know what they're worth when you die so enjoy while you can.
