Transmuting is the easiest money that i make. I have 6 alchemists and make about 168g a day just making primal earth in primal water. One of them is a transmute master (the other just got to 70 yesterday and the mounts too, so couldn't do the potion master quest yet). I say about a 4 months ago i was getting a proc every other day. Now it seems like i get a proc once a month if i am lucky, but i am still making the other 5 transmuting masters. The only reason is that i don't really buy pots or even make pots so having a pots master is not worth my while. I think at 350 you can go for the quest, yes you are right you should go do the pots master quest... easiest and cheapest, then pay the 150g and go transmuting. Go switch to trans master at 375 i think that is a waste of time to get the 25 skills in alchemy. I say this is because you get you primal to primal at 350 and they go yellow at 365 (i think) and go green at 375. But the ones that you discover don't go yellow until after 375. Been trans primal to primal for about 3 weeks and got my skill from 350 to 371 just making earth to water.

In short making pots from 350-375 is a waste if you are going to transmute everyday.