I always grow basil. About 4 square feet is enough to have pesto sauce once a week.
It's unfortunate that pine nuts are so expensive. We base most of our pesto on other nuts to save money, but you just can't beat the taste of a pine nut pesto IMO.
I make a vegan pesto using the following ingredients: basil, pine nuts, garlic, miso, olive oil. The miso adds the fermented and creamy flavor of the parmesan.
Remove stems from basil, wash and tap to dry, don't spin (a little water is good). Add ingredients to the food processor and blend until desired consistency. Scrape down sides and add oil as needed.