Is book marketing worth paying for, or should I just do it myself?

Honest answer: it depends entirely on whether the book is ready. Marketing multiplies whatever's already there. If the cover looks amateur or the first ten pages don't hold, paid promotion just buys you a faster look at that problem. Fix the book first — that's not us being noble, it's that we've watched people burn $2,000 on ads for a book the ads couldn't save. If the book IS ready, the cheapest real lever is your own list and a launch sequence, which costs time and not money. Paid ads make sense once you know your read-through — that is, once you have a second book, or a strong back-of-book funnel. Ask us what you're considering spending and on what, and we'll tell you straight whether we'd spend it.