When someone posts a fabulous find on Facebook, it looks easy. That person just went out and found those books with no effort, right? Wrong. Perhaps on that particular day they did, but what some collectors fail to understand is that the finder may have looked for books and found none on the previous couple dozen attempts. Nobody posts their failures on Facebook.
Think of all the time spent and gasoline burned on all of the failed attempts. That means that the cheap books purchased one day really cost a lot more in time and money. Is it fair to expect that person to give the books away for a low price?
When I have posted fabulous finds here, some readers assume I have the magic touch. I've had good luck, but I have had far more bad luck. Currently, I'm not looking for books very often, because all of my luck has been quite bad for quite a few consecutive attempts. Remember, nobody posts about their failures. I certainly don't.
The short answer is that there isn't an easy way to find cheap series books.
The long answer is that fairly cheap finds do exist, but the buyer has to be willing to put forth the necessary time and effort in order to locate those finds.
Book Sale Finder can help collectors find book sales in different regions. Search the Yellow Pages for book stores and antique shops. A frequent problem is that stores that are out of business sometimes appear in the yellow pages. I like to search for the store's name on Facebook to see if it has a Facebook page that has been updated recently. If so, that tells me quickly that the store is still in business.
While great finds can be found by taking a road trip, the better method is to purchase them online. In order to get cheap books online, one has to be willing to purchase bulk lots that might include extra books not needed. The extra books then must be sold. This is the best way to get cheap books consistently these days. The cheap bulk lots can usually be found on eBay. The cheap bulk lots are not available all the time, and a lot of buyers don't understand the secret to finding cheap books on eBay. The prospective buyer must search eBay every single day without fail, and it might take months and months to finally strike gold. If the buyer misses one day, that one day might be the day that someone lists a cheap bulk lot at too low of a price, and someone else gets it.
Some of the work can be eliminated by using eBay's saved searches. If that feature is utilized, then eBay will send an email each morning for the searches that have new results. The buyer can click on the links to see what has just come up for sale.
eBay isn't the only site where good books can be found. While the books are often cheaper on eBay, I have also sometimes found cheaper books on other sites. Anytime I want to build a set of books, I search everywhere online to find the best deals. I overlook nothing.
Goodwill stores list some of their vintage books online.
Here are some useful links to search engines that can help buyers locate books.
Not all sites pay for inclusion in the search engines. Amazon and AbeBooks are two notable sites that do not appear in Google's shopping search, for instance. AbeBooks has a saved searches feature that I have found quite useful. I have been able to purchase desired books right after they are listed. AbeBooks sends out the message as soon as a book becomes available.
Both Amazon and AbeBooks are very useful, but the buyer has to be careful. Avoid all listings that state that the book "comes with dust jacket if issued with one." This phrase means that the seller doesn't have the book and plans to purchase it from someone else. The buyer gets whatever the seller decides to purchase. It's far better for the buyer to find a seller who actually has the book instead of using a seller who does not.
Also avoid all listings that use the word "may," as in the book "may have writing inside," "may have water damage," or "may have tears." These sellers also don't own the book and plan to purchase a copy from another seller. Once again, find a seller who actually has the book.
Some sellers on Amazon and AbeBooks do take photographs of their books. I try to purchase from those sellers, if possible, and always get exactly what I expect. However, make sure the description is read carefully even when a listing has a photo. Look at the following screen capture of a deceptive AbeBooks listing. Click on it to see a larger version.
I highlighted the text that states that the book does not have a dust jacket. However, a jacket looks to be present from the main picture. A buyer could easily look at the rather high price of the book, see the picture of the jacket, and assume that the seller is offering a book with dust jacket.
The picture used in the AbeBooks listing was taken from a listing on Amazon from another seller. I purchased the book on Amazon from the other seller and at a lower price. The jacket has distinctive rubbing on the front panel. I am amused that I own the jacket that this seller shows in a listing currently up for sale.
I often have to purchase from Amazon and AbeBooks without photos, since most sellers do not photograph their books. When I purchase from listings that do not have photos, I make certain to select listings where the sellers are specific enough that I can be certain that the book meets my requirements and is actually in the seller's possession. I look for specific statements about the condition of the book and jacket, such as details about rubbing, tears, or chipping.
There are rival sites to eBay that are also useful for finding books, and the sellers usually photograph the books. While the selection tends to be poor, sometimes the books are priced better, and sometimes scarce books go unsold on other sites. When I wanted to find a Ted Wilford book to try, I found one on Etsy with no trouble. Of course since I purchased the book, it isn't there anymore, but this serves as an example of how books that are absent from eBay might be on another site.
Finding good books at reasonable prices is difficult. The prospective buyer has to persevere and search often, day after day and month after month. No matter how scarce a book is, it will show up for sale eventually.