Level 50: http://skyrimcalculator.com/#138809
Level 81: http://skyrimcalculator.com/#138810
The Level 50 layout should work for most any Merchant setup, but past that, it largely depends on playstyle. For the merchant I use, while they do have a Light Armor/Heavy Shield/1H Sword setup to start out with, by this point they're started to rely much much more on illusion and alteration to get by. Avoiding combat completely, as well as providing support for the hired help via alteration and restoration is more important at this point than being able to fight herself. As I play her as a lawful merchant, there's minimal investment into crime-oriented perks, though Extra Pockets is pretty much a must either way. While at the beginning I use The Lady stone for nostalgia's sake (loved that sign in Morrowind! Perfect for this build!), due to the changes of that sign, this build benefits far more from the Steed Stone instead.
As far as the stat layout is concerned, this one has me a bit more puzzled. Right now, I'm leaning 2:3:4 for the level up ratios, but I'm open to other suggestions, so long as you give reasoning behind them.
Remember, this is not a build that focus on combat. Buying low and selling high, that is how a trader gets things done. And the best way to buy is to get it free - so mine it, hunt it, and craft it yourself! Yes, it's a bit unorthodox of a build, but that's why it's fun.
