what would you substitute with this?

This is a great substitute for vanilla extract. Works in cookies, cakes, any other sweet baked goods.

is it pure vanilla ? what other ingredients are in this ? thank you

No... Pure Vanilla extract is the real thing whereas Vanillin powder is a man made synthetic product. That said, Vanillin powder is frequently used in cakes, creams, pudding, whipped cream, fruit, syrups and liqueurs. It provides good flavor and a wonderful smell to anything you bake. Vanillin powder is sometimes preferred over vanilla extract because it holds up better when baked whereas vanilla extract has a tendency to loose flavor when heated.

It’s $2 for the equivalent of 1 teaspoon of vanilla?

I do not know what $2 means for 1 teaspoon of sugar. I forgot the price of vanilla sugar per.bag, but i can tell you that it lasts a long time because i just sprinkle.a.bit of that sugar on my cakes since i do not like cake frostings which are too sweet for me.