I used to only buy in for $100 (my spread is $5 to $50). I was warned about buying in for $200-300 and betting nickels to start. Looks bad.
But I got tired of the count going up in the first shoe, and me having to go from a $5 bet to a $40 or $50 bet and not having the chips to do it.
I think it might look a little suspicious to be betting $5 for a while, then suddenly going into your pocket to buy in for another hundred when you have $35 worth of chips left in your stack.
"Sir, you don't have enough there for this bet?"
"Nah, I, uh, feel like betting 10 units... err... I wanna bet the farm on a hunch, that's it, a hunch!"