No regular weekly Vegas tourney gets 300 runners that I know of.
Binion's Saturday afternoon $125? Or The Orleans Saturday evening $100? AVP claims both get about 100 players.
Santa Fe used to do a once-a-month $10K guarantee that brought in ~100 players. They stopped, but I read somewhere recently it was about to restart. A bit of googling suggests it is commencing again starting Saturday Feb 23:
http://gamingtoday.com/vegasstyle/ve...nta_Fe_Station