Originally Posted by micromachine
30 will be fine as long as you are prepared to be disciplined about moving down if necessary, for example move up to 25nl at $750 but move back down to 10nl if it drops to $500.
Plus there's nothing to stop you from testing the waters at NL25. Just set aside 1 or 2 buyins and use them to see how comfortable or uncomfortable you are with the level of play and with having more money on the table.
And don't discount the latter. My case is similar to benevg's. When I got up to NL100, my roll was over 30 buyins. I won at a decent rate, albeit over a fairly small sample, but decided not to stay because I never got completely comfortable like I had at lower levels, and because even though my hourly win rate was higher, the difference wasn't important enough to offset my discomfort.