If you’re new to homestead, a medium house might make more sense so you can see if you like it. But both of those are really good houses...they have nice outdoor areas and pretty good interiors.
One other distinction...more expensive homes tend to get more air clearance. Homes have an invisible “roof” that limits how far up your character can go. I’ve never tested those homes...but as an example, the home in south bankorai has the roof set right at the roof of the house, so that you can’t actually even go up on the roof to build a patio setup. The roof for the reapers March house is about...oh...another 30 feet above the tip of the home’s roof. My Grand Topal Island has a roof like 18 stories in the air...waaaaaaay up.
If you want to build comtraptions or ramps or stuff, bigger homes let you go higher.