Updating the HVAC equipment

I’ve been using the same rickety old window A/C unit for almost a decade now. I’m impressed that the little motor inside the air conditioning unit is still spinning after all these years, but this little A/C unit is hardly working as well as it did when I first bought it. Since I live in a fairly mild climate, I don’t have any real need for a central A/C system that will only run my utility bill up high. Instead, I rely on exhaust fans in the attic, kitchen and bathroom to help with air circulation, while relying on the window A/C unit in the summer and spring to help with cooling down the house. I think the window A/C unit has lasted this long due to the light use that it gets, but I think this is definitely the last year that I can use it. While I’m tempted to stay the course and get a new window A/C unit, I’m also looking at the prospect of a ductless mini-split HVAC system. Since I usually rely on a fireplace to provide heat in the winter, I’m interested in the idea of a two-in-one system that can heat and cool the house, all without invasive ductwork installation. The ductless mini-split is arguably easy enough to be installed without professional assistance or oversight, and the expense of the entire system is much, much lower than a full-sized heating and air conditioning system. Besides, the energy usage of these ductless mini-split systems are still quite low! Though I’d spend less money still on a window A/C unit, I wouldn’t mind using a system that allows me to treat my fireplace as a decoration for the house.