Incense in general I'd say is a big no - you get probably 5-6 Pokémon per incense compared to usually 10+ per lure. If you want to level up fast then Lucky Eggs are definitely worth buying and then save them for when you have a lot of Pokémon ready to evolve at once for tonnes of exp. If you want lots of Pokémon, go for Lure Modules and Pokéballs (seems like a waste but trust me you'll need more balls when you start buying lures - always keep enough coins for some spare balls just in case). Incense is fine if you don't live near any PokéStops but that's about it really, I wouldn't encourage buying that really ever if you want to spend the money wisely. Incubators can be good based on how close you live to a good number of PokéStops for egg spamming.
Good advice. When I've used incense, though, I felt like I got a variety of Pokemon. On a lure, I feel like I only get the little stuff... MAYBE one decent pokemon in the midst of a bunch of weedles and rattatas.
I also like being able to move around with the incense... I hate being stuck in one place on the lure, lol.
But even so, I think you're right. Lures (especially combined with a Lucky Egg) are best for leveling.