This list is based completely on my opinion, but I think after being a reader for this long I know a little about what other readers might like. Still- every reader is different so not everyone will agree with these gifts.
Let's face it, everyone loves gifts, but what makes a gift special? In my opinion, a cherished gift is one someone did research on or had to listen to you in order to know and get it for you. Someone who takes time to notice things you love, to listen to you ramble about how much you adore something- then buy you something from that, well, it makes one feel loved. Focus on what the person you love has said, or has obsessed over and anything from those aspects in which they shared will mean the world.
Fifteen dollars and under;
Mugs
We light coffee, we like tea, readers LOVE a hot beverage, and though this might seem like a simple item, it is NOT. Most readers will have mugs, many mugs in facts, so you must choose the right mug for it to be special. Find a book they like, or a series they are into and get something specifically from that. They will be giddy I assure you. Maybe you noticed they always have a Stephen King book with them, or a sherlock lanyard, look into those to find your prized gift.
Literary tea
Yes- you heard me right. People actually make teas that are inspired by books and shows. This is a way for you to connect your giftee's favorite books to something practical they can use. Etsy is a good place to start, but there are many websites that sell such things- just google it.
A personalized page opener
These are often made of wood and can be very helpful for long hours of reading. It is used to keep the pages open with one hand so you can use the other to hold your tea of course. They are new and fun, and something I guarantee your giftee doesn't have.
Audiobook subscription
Some readers aren't the collecting type and aren't much for handheld reading, so try out audiobooks. You could get them something from Barnes and noble, or sign them up for an app of the company that has audiobooks they can buy. There are so many options for apps and companies and this just might help get your giftee into the reading groove (if they have been meaning to).
Books
Of course books, the more books the better, whether it be ebooks, physical books, or a gift card for audiobooks, readers just want more money for books. They don't care if they get the book or get money for the books- just. more. books.
25 dollars and under;
Book Protector
Book sleeves are great for your readers on the go because they protect their books from being damaged in their backpacks! They are padded sleeves for your book that sometimes have a zipper or button to latch closed to keep your book from sliding out. Bookbeau has some really awesome designs, and many sizes; Mini, Indie, XL, and Jumbo. If you are into supporting small businesses I also recommend Bookchicboutique on Etsy, which sells book sleeves as well.
Secret book box
These I always love, especially when they look so real! If your reader is very into collecting their books then this could be a fun gift they can use for their secret stash of money, bookmarks, or candy. Something book-related but also useable for other things! You can get them online, or even a store, like Hobby Lobby.
Book Fanart
Many books have fan art that is created of the settings or the characters, and it is something that is often passed over! You can go on Etsy, DeviantArt, Redbubble, and other small business websites and find art people have created for books and purchase a photo for your giftee to put up in their office or library. Get a photo of their favorite characters, or of something they have mentioned from the book and they will be so exact to have an actual photo of it. It's a one-of-a-kind gift.
Bookprops
What I mean by this is something from the book, like in the book. These kinds of gifts make readers explode with happiness. It could be a gem that the character carries around with them, a powerful necklace the love interest wears, a scarf the antagonist wears- anything that makes that book come alive. It makes the story so much more real and validates the emotions it gives your giftee.
40 dollars or under;
Personal Embosser
These are *chefs kiss* the cherry on top of any reader's personal library. This gives your reader the ability to stamp or emboss their private books, making them officially theirs. It's a personal gift that gives your readers collection so much more personalization and your giftee will cherish it.
A book crate
So everyone knows about the monthly subscription boxes that you can literally get for anything. Well, if you didn't know if you can get them for books too! There are many places that do this and some that will let you buy a single box rather than paying the whole subscription. (Super cool) It's something unique your giftee will appreciate because most of them come with a new book, bookmarks, candles, mugs, pins, and other little gifts. This could also help your reader if they have been on the fence about getting one, if they light it they might subscribe to the brand's monthly box. There is Owlcrate, Illumicrate, the Bookishbox, Fairyloot, and so many more.
Hope these were helpful, and you are able to find something unique and personal for your giftee/reader.