Are Stamps On Ebay Really Worth Buying?

That is a DANGEROUS assumption. In a perfect and ethical world that would be the case; in reality absolutely not.

Yes, this needs to be clarified with the seller ahead of time. If it's an expensive stamp that you'd want to send off for certification, ask the seller if they'll extend the return period until you get the cert back. Some reputable dealers will even foot the bill for the cert if it comes back bad. Anyway, revcollector is right - don't just assume you'll get your money back if you get a bad cert, particularly when buying on ebay.

Not saying that you are doing this but it is a common mistake of many new hobbyists is to constantly assume that they have rare stamps. Working under that assumption, they then go out and justify their position by searching for highest priced online listing they can find. (You can find many threads in this forum which are like this.)

Simply put, they are misdirected due to the incorrect assumption that they always have rare stamps. (This is a hard message to deliver, the 'hunt' for rare stamps of one of the things that makes our hobby fun and interesting.) But everyone is better served if hobbyists always assume the opposite; that they do NOT have rare stamps. As you work through the identification process start with idea that you are holding the most common stamp, then work upward though the other, rarer, possibilities. If at the end of your ID process you still think you have a rare stamp, then assume it may be a fake or forgery. At this point you can use a forum like this one to seek others input before you decide if you want to spend money on a cert.

One of the silliest ideas is that anyone would use a forum like this as the only expertzation tool for a rare stamp. If you are going to try to sell a rare stamp, it needs to either be listed as 'possible' or have a cert. If you are going to mount it in your collection, it should be noted as 'possible' or 'needs cert'. Getting input from other folks is a fine method for figuring out if you should spend money/time on getting a cert but you shouldn't starting planning on retirement based upon an online image ID from a usually anonymous opinion. Nor do you want to be defending a listing with "gee, some guy on a forum said it was real" or set your family's expectation that your collection is worth millions.

As for buying, use sellers with good, well known reputations. Educate yourself with a large amount of knowledge before buying expensive stamps, especially if doing this online. Hearing stories about rare stamps being bought for next to nothing are fun but this doesn't happen often. Many times these stories are from hobbyists with decades of experience and very deep knowledge of a specialized area. Yes, even a blind squirrel can find a nut but it is exceeding unusual that this would happen. The chances of a person misidentifying a stamp, or being taken by an unethical seller, are much greater than stumbling upon a rare, unidentified stamp.
Don

Catalog value is just a reference, it doesn't have to reflect real value, nor scarcity. Note that many times catalogs are published by dealers.

I'm thinking about a particular stamp I'm willing to buy at 2000% catalog even if faulty. I regularly buy some at 200% catalog, while I won't go over 10-25% for others.

The hobby aspect will result in collectors buying individual stamps on e- bay when they could buy a complete collection of an issue from an auction house for a lot less. Dealers take advantage of this, I noticed that a dealer bought a nearly complete collection on Scott pages from Kelleher for 20% SCV and is now liquidating it with 38 auction listings on e-bay. The dealer didn't scan the backs and doesn't mention in the listings that all the stamps were hinged. I don't like to see such recycling of collections; what's wrong with the hobby when dealers think they can make a living doing this?

Without doubt ebay is a valuable resource, my collection is vastly improved by what has been offered there. Mind you, I don't see the volume of interesting material that I used to, but there are plenty of bargains to be had. Googling the seller name is a good idea to check for bad reports or profiles on other sites (Delcampe, TradeMe, BidorBuy as examples).

I still can get the odd good deal on ebay....often a dealer will start with a low bid, with the hopes that it will eventually bring in enough bids to reach the expected payoff...then at times traffic or interest to that item may be low...advantage buyer.
Not often the case...but it's a crap shoot....that's why a lot of sellers go the 'buy it now' route..so they are at least guaranteed the price they want. A lot of the stamps that i'm interested in fall into that category and our out of my price range even at half of catalog value.

I know four or five club members who are long time ebay sellers who gave up on auction style selling , they all use buy-it-now because there is a serious lack of open bidding and all of them agree that the last minute bidding is around the opening bid price. They all agree they are tired of giving away material .The thinking now among the guys is ask a price and wait .

As I browse stamp stuff on ebay, I see I can buy good usable US postage (post 1940) for well under face value but sellers want $10+ for 10-15 year old Scott annual supplements. The money is not in the stamps, it is in the supplies if they were selling at those prices (they are not moving well).

Al