Yea, it might cost $200-300ish to have a certain Standard deck, or half way decent collection to make multiple decks from, but you don't need to spend that all at once, or even at all sometimes. See the comments about Draft above. Considering you were good at Limited before, it can be a much cheaper way to build up your collection then just buying singles.
Also, there's a couple very competitive decks right now that you can make for under $100. The Jeskai Heroic Combo deck is legit, and other then about $60 in lands that are good to have if you want to make other decks, it's all commons/uncommons really. Or, Boss Sligh, R/W heroic, or U/W heroic are all decks you can make for maybe $50-100 just buying every single card from a website.
It's all a matter of how much time you want to spend. If you play drafts (well), make decent trades and pay attention to the overall meta going on.. then magic is maybe a $20 a week hobby.
If you want to immediately buy an entire deck outright, you'll likely spend closer to $200, yes.
I always suggest to newer, but smart, players to wait for a pre-release weekend and try to keep up with the sets from that
point on. Wait a bit to get into Standard as you build up cards from Sealed and draft, plus get used to the cards in those formats so you have a good idea of the card pool at the time.