Experiences with tiny houses or mobile homes, vs old house?

Hi everyone! My wife and I are looking to buy some land to do a little farming for ourselves, in light of the long descent, and we're looking for land close to the city where we live for all the amenities it offers, not to mention our jobs, but far enough away to get land cheaply.

We're considering: a) a bigger 'tiny house' (700+ square feet, some of what is marketed as tiny homes are that large and have foundations), b) a mobile home, or c) an old house (there are a couple available). We don't have kids, and very likely won't have any.

Just wondering if anyone has any advice about the pros and cons of each? Many of the old houses around here are too big for two people, plus many have problems due to their age, yet I've heard that tiny and mobile homes have their drawbacks as well.

We're not interested whatsoever in the shiny, modern homes that are most common in Nova Scotia (where we are), not only do we not like the look of them, we are trying to avoid as much debt as we can.

Thanks in advance!