I guess I'll add my thoughts about ebay. You'd be hard pressed to find coins sold on ebay where the buyer did not pay too much ! In most cases, you can find the same coin, same grade, for less money in a dealer's shop, or in an auction. For the most part, ebay is populated by bidiots when it comes to buyers ! Are there exceptions to this ? Yes of course, but they are few and far between. And for a novice or beginner, and even intermediate collectors, to try and buy coins on ebay is about as dangerous as trying to walk through a mine field while on crutches and wearing a blindfold.
Jake, here's a little thing that I do...if you can afford the time. Pick a coin with date and mm that you are interested in and watch the bids and win price on that particular coin. After you see 6 to 10 of them sold, you can establish a "base price" for that date and grade...and go from there. Remember of course that slabbed coins are almost always higher in price than raw coins.
When I travel I go online and look for coin clubs, coin shows, etc. Several towns in central Florida have monthly shows, and they are usually scheduled on different weekends. There is usually not a lot for sale at our monthly club meeting here in West Tennessee, but it is generally a good place to buy because so many of the oldtimers expect to buy below Greysheet. As for prices, Red Book has always been considered "high" in most instances and possibly out of date by the time it is printed, but in a fluctuating silver market even the weekly Greysheet can be off from the time it is printed until it arrives in the mail. There is valuable information in Redbook. On collectible coins, rather than bullion, prices don't seem to fluctuate that much from week to week.
I am a collector of Irish, Canadian and Japanese coins tih occasional forays into Latin America. I watch E-Bay, Heritage, SixBid and Spink's to keep abreast of market prices. The PCGS auction results cited in an earlier thread covers only U.S. coins (I think). In the international coin world you have the cast your net wider. Above all, education and a trusted dealer(s) are imperatives. Welcome to CT which I think is one of the better English language forums.
I'll also add this...anytime you see a coin listed as an "Estate find", use caution, especially on raw, key date Morgans.
One guide to wholesale prices that is worthwhile is NumisMedia Wholesale, which can be found at numismedia.com. Also, do an advanced search on eBay to look at what items have sold for in particular grades. The Blue Book, Handbook of United States Coins, is supposed to be a guide to wholesale prices, but the values are typically quite low.
Hi Jake, welcome to the forum. One thing that is very important is that you should develop a working knowledge on how to evaluate/grade the condition of coins. Buying stuff on offerup, etc can be risky if you don't know how to spot counterfeits or determine the condition. The price of some coins can differ greatly from one grade to the next. Lots of good info posted here for you, use it and look at a lot of coins. The more coins you examine, the better you'll become at spotting problems. Post any other questions here, we're always happy to help! Nick
Digital Coinage mag is $10.00 per year and they archive your mags. COINS mag delivered $23, Numismatic News for just $29, Digital Kindle versions of these, reviews of coin mags on-line, other forums: CoinWeek for example. Good hunting!
I find myself gravitating more toward Heritage as of late. There seems to be less variation in pricing and the photos are more uniform. eBay is a crap shoot with a lot of "juiced" photos and lots of dreck, especially in the no reserve "pure" auctions. Slabs are no guarantee, as I've ended up with bad dip jobs that probably turned later in their holders. I have gotten quite a few coins I am happy with though, for fair prices. Also eBay is better for returns. I think the prices for slabbed material are a bit more predictable in general, perhaps due to more informed buyers.