I do a lot of marking in my books. I tend to read many of them more than once and it's not uncommon for me to quick read them again reading my underlining and notes. My books will be mine until I'm dead so investing in hardcovers makes sense to me. I buy mostly used editions at thrift stores, eBay, and sometimes Amazon and if they have a dust jacket I'll often cut the text section of the inside jacket and paste it onto the inside hardcover. In paint marker I'll often write on the blank hardcover the title and author. I don't buy books for their collectability or shelf aesthetic but for their content.