If you 420, then you should be more than ready for big clouds Direct to Lung hits. If you've vaped your friends and didn't cough a lung up, you know if you are ready for 60w to 100w+ vaping.
If you like the look of that smok, it's cheap enough @ $50, go for it. You certainly won't use 300w or even 200w, smok is not a very good brand, but that's a cheap price so if it's the look that attracts you to it... no harm, no foul.
If you smoke cigarettes and this may end up cutting down on your consumption, then that's money well spent. You may also get dual use out of it with your 420 but that's not something we can discuss in this forum.
Freemind and others have many good points and in my opinion there are many better mods for $50 or less but it's your money.
But do us a favor and when you do get tempted to hit it at 300w... post a vid of it here would ya?