Maybe should also ask what you plan on plowing? Plowing is great for fields. I also like a plow for establishing a new garden. Even an existing garden I like plowing in fall and turning the trash under to decompose and feed the next years crop but many dont do that. For gardens, most like a rotary tiller. A plow isnt a single pass tool like a tiller. You also need a disc. The cost of a plow and disc that are worth a darn are pushing the price of a tiller. Usually when I see the old 2-bottom plows.....if they dont need new points/shares and are in field condition and nothing broke....they are ~$300. And a disc is ~$600. Alot of money for single purpose tools to be used once a year.
Between facebook market place and craigslist.....I could probably spend a day driving in a 60 mile radius from my house and pick up at least a dozen 2-bottom plows for ~$300