Reminds me of my brother-in-law. Had a part-time job at a large, local farm when he was in high school. One afternoon, my mother-in-law, who lives in a subdivision on 1/3 acre lot, sees this HUGE articulated tractor drive past her house and there's her son driving. He proceeds to plow the vacant 1/4 acre lot next to them in two passes and leaves. Later that afternoon he came back and planted 1/4 acre of cabbage left over he got from the farmer. Had a grand idea to sell that cabbage for profit. Well, come fall, he sold a couple head, but most of it started to rot after the first frost and stunk up the entire subdivision..... rotting cabbage. :laughing:
As to your original question, we have a small machine that we use here on our 1 acre lot. 60" finish mower, a couple buckets, a power angle 60" snow blade, pallet forks. Really handy to be able to mow the lawn in 20 minutes, move landscaping material, firewood, work in the garden, etc... we also take it out to our remote property to maintain the trails with a 48" brush cutter, and to gather firewood to bring home. And we used to maintain a Little League park with 4 ball diamonds and the wife's church ball diamond with it as well. And do some small jobs for friends and family.
So the answer to your question(s) is what type of jobs do you need to do, what type of machine do you need to do those jobs, how much time do you have to do those jobs, and what size machine can you afford on your budget? Then you need to adjust the size to your time budget and money budget to find a happy medium.