Basic Blackjack Strategy Question – Making Money?

I know using the basic blackjack strategy at a casino the house still has a slight advantage and will mathematically always win in the long run. But can a player win in the short run? For example, what if I went to a casino with $1000 with an objective to win only half of that and leave with $500 in winnings. How possible and how long would it take to achieve that goal assuming I play perfect blackjack and play 15 or 25 dollar hands.

 
 

When you are card counting the regular way, when should you start making big bets (blackjack)?

I’ve known how to play blackjack for years but I never got into it until like a couple weeks ago. Ive been researching about card counting and I was just wondering when I should make big bets. The casino works with 6 decks and I understand that 2-6 is +1 and 10-Ace is -1……so should I wait until 3 or 4 decks of cards have been dealt and then make bigger bets if the count is good? Or should I start betting higher as soon as the count is a +?