I play 3/6 at commerce and everyone plays with $1 chips. Lots of people play out of racks which slows play, but is allowed (I guess). Some people buy in for as little as $40, but they tend to keep pulling $20s out of their pocket and lots of cash gets mixed into the chips on the table. Not only that, these guys tend to only have $20 in chips in front of them when they catch a monster hand and can't take advantage of it because they're all in by the turn. I prefer to buy in for $200 in chips - it makes a 4-3-2-1 pyramid and I never have to worry about rebuying chips. I find that having more chips on the table tends to give your bets slightly more respect and you will always have enough to take full advantage of a monster hand. If I win several big pots, people tend to need to rebuy so I sell them their chips back for cash.