Started gardening with my parents as a teenager. It's something I return to again each spring, adding more knowledge little by little. Some years were too busy to grow my own seeds but I always grew tomatoes, basil and a few flowers. That is my base level. Then other years, like recently, I grow everything from seeds, save seeds, swap seeds, have compost going, worm bin, lots of ornamentals and enough veggies that I hardly have to buy any.
As far as it being expensive I try to spend as little as possible, which is why I compost and swap seeds. For Christmas and birthday gifts I have s supply of extra Tubers, seeds, herbs and seedlings that my good friends appreciate. So I spend less money in gift type items as well.