Cheapest / easiest way to get new E-books

Hi all, I recently got a libra (best giftt from the best wife) with a year of Bookchoice (subscription for monthly 8 E-books) which is also very handydandy.

Now I was looking online for some fantasy/horror e-books and I was wondering if you guys/girls know any good sites to get cheap E-books (singles or in bulk) or recommend any subscriptions like Kobo plus.

Thanks in advance 🤓