everything that has to do with Harley Queen excites me a lot,

You'd love this then! It's only three volumes long, but it's really, really good and goes into the creation of the character.

I prefer the physical edition,

Yeah I do too. I wish I could've purchased it, but now that I think about it, it was only one volume on the shelf, not just super expensive. There aren't really comic book shops in this part of the world, so seeing anything in any shop is a surprise, but a comic that'd be 5 - 8 GBP back in England would be almost 20 here!

If you do end up reading it, get a review or something out about it, it'd be cool to see someone else share their thoughts on it.