Since I'm not selling or appraising anything I own, I gave up on keeping track of total value years ago. I don't even keep track of total spent. Sure, a couple hundred $5 coins adds up, but you'll never know how much anything is actually worth until you sell it. After a year or two you'll just have to go through the whole process again if you want an accurate number.
Or you can use software like I mentioned earlier (I use CoinManage but there are others). Their value tables are automatically updated each year.
Large cents, especially nice ones, are a lot more expensive than they used to be. I have dabbling with a one a year set, and even the common dates run into money I paid $225 for nice looking 1826 in VF-25 at last week’s FUN show. I started out thinking I’d build the set in AU and Brown Unc., but that goal is too steep.
Yes, dealer-to-dealer. CDN publishes a retail price guide quarterly called "CPG Coin & Currency Market Review".
The Grey Sheet is supposed to be the wholesale price, but a lot of collectors think they are entitled to pay those prices. Some of them also think that they should be able to get those prices when they try to sell their coins. That would leave the dealer with minus income since the cost of goods sold is only one of a dealer's expenses. I go though and drop in the Grey Sheet prices for my U.S. coins every six months on so. Some of the coins are worth more and some are worth less. Some of the Grey Sheet prices are "dream numbers" for dealers. You can't buy some things, like properly graded, no problem early U.S. coins for those numbers. A dealer has to pay more and naturally charge more for those coins. Here's the 1826 large cent. You can decide if this was a fair deal or if I got hosed. I can't find these coins "on the cheap" without problems.
I mean in theory the old Blue Sheet was sight-unseen and the Grey Sheet was sight-seen dealer buy prices. The spread covered some portion of the risk between not seeing and seeing. Much like the Bluebook was dealer buy price and the Redbook was dealer sell price. Always assuming a nice dealer, with real chairs - not held together with duct tape - working lights, and a clean (no mustard stains) bowling shirt on the proprietor.
451 sounds like a lot of coins. I started out with over 500+ coins. My brother and I split our father's coin collection. There were over 1,000 then. My brother took his coins and put them in a box, closed the door and never looked back. I tried to buy them from him, but he tells me it's Dad's legacy and he doesn't want to part with his coins. Anyway, I was in my 60's when I got Dad's coins and it got me going. I have no idea what my son will do with my collection, but I'll be dead and past caring.