Realistically, you should only bet more money in blackjack when you are counting cards and you know that the count is in your favor because there are a lot of 10-value cards remaining to be played.
To those not familiar, when looking at a blackjack table in a casino you can always find the minimum and maximum bets allowed. These will usually be in a range such as $10 minimum andR$1,000 maximum (10/1000).
