I need to preface this guide by explaining that this was written primarily for an Australian audience so keep in mind that we're on the bottom half of the world & we have our seasons & school vacations at different times to everyone in the northern hemisphere. We have our major school vacation in December/January - keep this in mind when reading - it will apply to different months in your country.
Start of the school year means costly text books, stationery, uniforms, school fees and a whole lot more. With many parents having 2 or 3 children at secondary school at the same time, it can be a financial nightmare. However, you can make it a lot easier on yourself . While sometimes schools and booksellers have second-hand book sales, the quality of the books is often not too flash and a substantial amount is still paid for these books. I slash dollars off my kids' booklists every year by searching and buying through eBay.
The best time to start searching for your children's school textbooks is around November. Why? Senior students are finishing off exams and text books are often finished with. Then as the younger students wind down, their old textbooks start appearing on eBay, usually in mid-December. Some Maths & Science books will cost you close to $50 new but you can pick up a few bargains over the summer holidays as parents begin selling books their children have finished with. Why don't they keep them for younger siblings? Often textbooks are updated every couple of years so by the time the younger one needs the book, it's the wrong edition. So if you're in the selling game, don't hold on to those books for too long otherwise you'll be stuck with an obsolete book! Sell it early and re-coup some of your textbook spending!
Novels are a different story, however and because the text doesn't change, the book is still current. the cover might be different but - so what? Is it worth paying full price for that? Some second-hand texts are nearly in pristine condition while others, more worn, come with handy annotations in margins! Some schools teach the same texts at the same year level for years on end, particularly if the school is fairly traditional and sticks to some of the classics. There's usually an abundance of these around and even with postage factored in, you can easily make a huge saving. A new novel, which will cost around $20 can be picked up for maybe $2-3 plus $1-$2.50 for postage (ALWAYS check postage costs carefully and factor them into the cost equation).
You have to be patient! If you bid desperately, you won't make much of a saving. Do daily searches. I use the "My Favourite Searches" function for all text books so it just takes one click to find what I'm looking for.
Stationery works a little differently to textbooks - generally, you'll find items cheaper in regular shops during "Back to School" sales. But... when you see those dreaded graphics calculators on the maths booklist and nearly pass out when you see the near $200 price tag alongside it, think eBay! I bought mine, brand new with postage, for exactly half that price about a year and a half back. Items like these have to be watched during "non-peak" times - that is, not at the end of the school year or start of a new one! Fewer people are buying calculators in the middle of the school year so you'll have less competition bidding against you.
Remember there are many other school-related purchases you can make on eBay too, ranging from leather school shoes and other uniform items to terrific desks for your children to work on at home. You can buy many of your school needs without even leaving your home. It just takes a little thought and some online searching.