While I have little to no experience with them, the math would suggest that your chances of gaining money with cs are greater then your chances of gaining money with LS. Imagine that you are on a four hour long trip with 5 people. Your group would be lucky to get one or two "rare" drops. Now unless you have a lsp equal to that of someone who had 3 arcane sigils sniped, then chances are (in a group of 5 remember) you will recieve neither drop. Now also keep in mind that it takes money to make money, so in the time that you spent finally getting a "rare" drop, you could have spent the money earned on many smaller drops to merchant or invest in skills. Plus I think that CS is just more fair.