My partner said that when he'd move in with me, he'd pay his share. His logic is that he's currently paying a landlord and he'd rather pay me. That way I get more financial room to loan money again (I own my apartment, but have a mortgage), and he'd pay less than current rent, allowing him to expand on a down-payment buffer. Ideally this way we could upgrade to a small house in time, suitability split, and I keep the apartment to rent out or I can sell it.

There is power in combined finances, but you need to take into account what you'd do on your own. That said, I would prefer to be in a situation where I could just let him move in for free, as life is expensive enough already.

But I also believe that it is essential to a good relationship that each carries their reasonable share. I grew up with my mom fully depending on my dad for finances as she was a stay at home mother. I loved she was always there for us, but when my parents grew apart, she really struggled and dealt with a lot of guilt because she couldn't provide for us as before. This is why I've always made sure I could make my own way. My apartment isn't the greatest but I'm thankful every day I can benefit from ownership.