If you were going to transmute the soulstones in the first place to make an element/package, why would you even consider their value? By buying soulstones and then transmuting, you are losing money. You can easily get the required amount of soulstones to transmute elements through dailies and PvP. Meese failed to mention that Elder Elements/Jewels are tradeable, and go for a nice bit of gold if you sell one on the market. You save and potentially make more of a profit getting the soulstones yourself and transmuting packages than you would ever get feeding blues for small exp gains.
To be honest for transmute u use 5 soulstones and 50 silver and some powder ...wiht this basic cost it got me like a bit over half of 1 bar....its not worth it at least in my eyes, for me the cheapest way is to use those blue weapons that drop in the 12 man instances...
Even if u farm soulstones for transmute u look at the overall cost...so5x 35 silver + 50 silver= 2.25 gold, for that amount i got like 15% of my true siren axe. if i use blue weapons and i pay 10 silver per weapon....from 22 weapons i get way more than 15%
Its only cheap in the moment. In the long run, the elements win. Element packages give you anywhere from 2-4, with a potential one being sellable on the market for an average of 3g on the NA servers. It only costs 1 silver per element as opposed to a handful of silver with one blue. You are not saving money by feeding your HM weapon random blues you find more . You should be salvaging those for element powders to make your overall progression faster. I don't really know how I can word this any simpler: feeding your weapon other blues stops being cost effective when you hit Awakened Profane.
Didnt try yet those element packages only that single purple element for weapon which requires 5x soulstones , el powder and 50 silver. maybe the package is more worth but like i say from what i see , at least for me blue weapons where cheaper as that single element. and i dont speak about how muchj powders cost cuse those u get anyway from weapons. but the soulstones, cuse even if u farm them...they are like 35 s/1