I got weirdly obsessed with public domain archives a few years back. A ton of early 20th-century romance, the kind with heaving bosoms on the cover, is out of copyright. Project Gutenberg has a section for 'love stories' but you have to dig—look for authors like Georgette Heyer (though not all her stuff is free there), or even some older Baroness Orczy novels that aren't just 'The Scarlet Pimpernel'. The language is dated but the drama isn't.
Libraries are the unsung hero here. The Libby app linked to my card lets me borrow contemporary historical romance ebooks without waiting weeks sometimes, if the library's collection is decent. It's not 'owning' them, but for a quick fix of a Julia Quinn or Lisa Kleypas novel I missed, it works.
I've also had luck with author newsletters. Some newer indie authors in the genre will offer a free prequel novella as a sign-up incentive. The quality varies wildly, but it's a solid way to discover someone you might want to pay for later. I found one of my favorite Viking-era authors that way, from a promo in a Facebook reader group.