Lots of small farms for sale in Southern European countries whose economies are in bad shape. Chinese investors are buying farms in Portugal, for example.
Suppose you buy a small farm in Portugal, Italy, Greece, or Spain. Say, 10 acres. You use 8 acres to plant orchards. Oranges are too cheap, and it's hard to compete with Brazil in the orange market, so go for fruits that grow in more mild climates and whose price per pound is high enough. I heard that
pomegranates are a good investment. Cherries may be interesting, too, even if only for the beautiful cherry blossoms.
So, 8 acres of orchards. No need to mow the grass. Just buy a cow, and let her graze. And she produces some 5 gallons (= 20 liters) of milk per day. Lots of butter, cheese, and yoghurt. Plant some cabbage, lettuce, tomatoes, potatoes, beets, etc. Read some books on farming, learn from people who really know what they are doing.
Once you attain a sufficiently high level of knowledge and experience, it's time to acquire servants and relax. There's something called
World Wide Opportunities on Organic Farms (WWOOF), which is like CouchSurfing for farms. Lots of young hippies all over Europe willing to work in organic farms in exchange for food and accommodation. Some of them are cute girls. Just build a small guest house for them, and they will be your willing slaves. Cost of labor = zero dollars. Sure, they cost food, electricity, and gas. But you can use vegetables you grow on your farm to feed them. Fortunately, lots of WWOOF'ers are vegetarian, which makes them even cheaper! Here are some WWOOF'ers in Portugal:
Ideal would be to plant 4 types of fruit-producing trees, one for each season of the year. Then, you could host WWOOF'ers for 2-3 weeks per season, when it's time to pick fruit. Remember
Tom Sawyer whitewashing the fence!! Make it look like lots of fun, and you will find decadent urbanites willing to work for you for free. This is my retirement plan.