The point of taking the feat and paying for the rituals is flexibility. Sure, you could buy the alchemist's fire in town and head out. Cheaper, assuming that's what you need. Or you could learn several different rituals, then buy a couple hundred GP worth of alchemical components, get to the dungeon, scout out your foes, then pull back and whip up the exact alchemical items you need for the fight. I'm not saying it's a must-have or anything, but it certainly is a viable option, especially if you play in campaigns where you may not see a town for 4-5 sessions.
The point is alchemy gives you an option to do something that your at-wills can't. So yes, that large wad of cash you dropped DOES beat your at-will powers.
Something I didn't see addressed here by anyone (and I don't have AV yet so it may be in there) is how people selling alchemist items make a profit. Why would he local merchant sell items for exactly what it costs them in materials to make. I know 4E has shied away from crafting and profession skills to be more tactical but it seems rather jarring to me that they should be so blatant about the economy.
You won't like this answer, either, but:Something I didn't see addressed here by anyone (and I don't have AV yet so it may be in there) is how people selling alchemist items make a profit. Why would he local merchant sell items for exactly what it costs them in materials to make. I know 4E has shied away from crafting and profession skills to be more tactical but it seems rather jarring to me that they should be so blatant about the economy.