On my first time I did a gram. It was alright. The second time I bought 240$ worth (about 4 grams, and sniffed it up in like 2 hours. I overdosed and was fucked up majorly cuz i was doing like 10 lines every 2 minutes. But yah....2 lines is good to start off with. I found that i could take like tons of lines of the pure high grade shit and not die so meh you should be okay. I don't do it anymore, it's expensive and bad for you. So use wisely. 2 lines should be okay to give you a buzz. But you could probably take a whole lot and be okay depending on the purity. But i don't know anything about you so you may get messed up off of 2 big lines.......so be careful.