don't worry about reputation. it maters not at all. besides, it doesn't go down with pickpocketing anyway.
there is a trick to taking all
but one of a particular item that has been pointed out in the forums (search for pickpocket) - but i used a different technique.
let's say you have 7 levels of pickpocket. you'll be able to take a number of items form the BF merchants - but there were only two things i would steal (after patch 1.45), gold and the gold charms i WOULD USE.
when you see an item(s) you like, purchase it. hopefully you'll find more than one item at the merchant. the gold you just paid with will be added to the merchant's gold inventory (usually 5,000-21,000). as long as the pile of gold the merchant has DOESN'T exceed 50,000, you can steal back everything you spent plus.
this way you get all the items you want, plus a boatload of gold.
don't buy the gold charms, they cost over 50,000 (thus making two piles = two steals).
when you find the post on taking everything but one, you'll see how you could actually combine the two ideas.
i had so much gold that i stopped collecting anything at all from act III onward (the pic is from act II).
because i had a bow user and sword fighter, i ONLY took agility, strength and survival charms. your character build will determine which you should take.
i finished with about 2 and a half million gold and here are the (almost) finishing charms -
DK charms zan charms 
