no. For 1/2 NL a buy in is $200, so in order to have 20 buyins you need a role of $4k

Also, if you are asking these kinds of questions i reckon you'd get crushed at 200nl.

If your a newbie cut your teeth at 5nl (0.02/0.05) or 10nl (0.05/0.10) and build a role and move up the levels