You might have an easier time finding that in a market, or corner store, than a supermarket, but you might not find everything you are looking for, and it might all be a bit more expensive than a supermarket. Depending on how many placed you go to show (taking more time), buying smaller portions at smaller stores may end up taking more time and cost close to the same amount as the larger portion. There's not a lot of incentive in that besides not being wasteful.

Also, you're probably unlikely to find much measured to 100 or 200 grams in any US supermarket. It's all ounces (both fluid and otherwise!) here. ;)