In my opinion; it all depends on the format.
However, the best way I find to save is looking out for sales. You can still drop a good amount of money, and it may not seem like saving, but if there are many things on sale; go for it. I remember when Toys "R" Us had a sale over here, I spent at least $24 for over 8 packs worth + promos + more.
So you can get some good bang for your buck with those.
If you're just starting out, don't expect to get into the competitive scene too quickly.
Buy a deck that you like, with Pokemon you like, get in your comfort zone and get used to the way some of them play, or practice with a friend's deck. If you've got a preferred style of play, look for a deck you like that fits that style, slowly build upon that deck, constantly upgrading it. Over time, some cards may remain, or be switched with a similar one (Example: A new Escavalier comes out and you like it more than the Escavalier from your starter deck, replace it with whichever one you like better). It's a lot easier on you to get into the comfort zone when playing a game, because that way you have a lot more fun, and it's very easy on your wallet.