[Gramps]

If you don't have a fat bankroll (like 5k) to play the 100's, and you multi-table, work them in slowly (1 to go along with your 50s). Good way to gain some experience/confidence at a new level without playing above your BR. Heck, if I'm getting my arse beaten up at my current level, I still drop down for a while to lick my wounds, even with a sufficient bankroll to stay where I'm at.

...but if you're taking a stab at 100's only on a short bankroll, you have a very real ROR. That's bad poker, and if things start going against you, it can only further affect one's game for the worse (no matter how determined one is not to tilt, etc.). No shame in working into a new level slowly - minimizing your downside risk is good investing (which is all poker is for a winning player). It's a good long-run exercise in discipline too that can only pay dividends down the road.

If you're crushing the 50's, you will do very well in the 100's in the long run - just always respect the BR requirements and inherent variance of the game.