Mini split vs. 3rd zone HVAC for dedicated basement HT

Basement home theater in unfinished portion 25' X 17'. The room is right next to utlities, but due to a lot of duct work already running through the area, the ductwork for a 3rd zone with it's own supply and returns will be a challenge and will add quite a bit of labor cost. The guys have quoted me $6,000 for the third zone, and $3,000 to do the mitsubishi mini split.


With the 3rd zone, heating the room is not too much of a concern, but keeping it cool when the room has people in it is. This requires some equipment that allows the air condition to work even if it is

I personally prefer the 3rd zone concept, but my wife thinks both options are nuts cost wise. Her brother is a carpenter and she thinks by proxy that just adding the returns and supplies like we have for the rest of the basement will be fine, and opening and closing the vents in the lower level as needed to regulate temp. My contractor is not super savvy in HVAC for theater so I am having to guide him and frankly, I am not 100% sure despite reading this forum for a while.


Anyone have any testimonials or thoughts of 3rd zone vs. mini split on price structure, benefit vs. cost? Live in Wisconsin so it can be 110 or - 30 degrees.


Thanks.