Is basil grown for essential oil different from culinary basil and is the oil worth it?

Yes, they are usually different. Culinary sweet basil is grown for tender fresh leaf and sold by weight to kitchens. Basil grown for essential oil is a different use of the crop, where the herb is harvested, sometimes wilted, and steam distilled. The two main commercial oil types are methyl chavicol rich basil and methyl cinnamate or linalool types, and buyers care a lot about the chemical profile, so you must grow the variety the oil buyer specifies. Oil recovery from fresh basil herb is low, often in the rough range of 0.1 to 0.4 percent of fresh herb weight, meaning you need a large tonnage of herb to make a meaningful quantity of oil, and distillation needs a steam still. For a small farmer, running your own basil distillation rarely pays unless you have scale, a clear oil buyer, and the variety they want. The oil market is specialised and price varies a lot by quality and chemotype, so do not assume a fixed rate. If your land is small and a city is nearby, selling fresh culinary basil by weight usually gives a better and faster return than chasing oil. Get oil yield, the exact variety, and the buyer's price in writing before you commit.