Is there any Amalgamated Gemstone recipe that's more cost-effective than simply selling the ingredients and buying a Gemstone on the Trading Post?
Due to the large number of possible recipes, the most efficient ones change daily, if not hourly. For example, as of time of writing, the most efficient recipe (1.6278g) uses 75 Gold Doubloons, but that may change later into Emerald Shards (which are used to upgrade to Emerald Orbs).
That said, as far as I've observed, crafting has always been cheaper than buying from the TP (as of time of writing, Amalgamated Gemstones are 1.8919g each, buy price), even if you don't take into consideration the rare occurrence of getting 25 Gemstones with the same recipe.
"Thief? How rude! I'm a Procurement Specialist." -Glenn Gynnafante
https://gw2.silveress.ie/gemstones is a real-time tracker tool that you can use to check on the amalgamated gemstone forging market.
Answers
Personally I find it better to craft, atbut least with the current fairly low component prices. Just grab whatever's cheapest at the moment.
That depends. I am not sure if there is enough data gathered for the proc rate of the two forge recipes. I've been told the rate was 5%. At 5% either recipe would be better than buying AGs directly BUT(and that is a huge BUT) only if you are going to make a very large number of AGs. For example theoretically the recipe that generates 10 is best but to get 250 your maximum sample size is only 25.
On average with current prices you could save around 50g per 250 AGs but that is only you are making enough so that unlucky streaks doesn't screw you over.
You don't really need luck - remember that the 3x25 orb recipe always generates at least 10. By my calculations, getting no "crits" at all you're usually about even with buying gemstones straight up. Every crit reduces your costs.
If I buy orbs at 20s each on average, 10 x the 10 AG recipe costs approx 159g (3 stacks of orbs at 50g/stack + 50 ecto). That means 1.59g/AG assuming no crits.
Edit: Caveat - it seems the orb prices have risen a bit these last few days!
My method is definitly one for patience as it requires buying the orbs when they're relatively cheap, but there's usually a few at below 20s.
Thanks, everyone.
If we consider the 1 gemstone recipe vs the 10. you get a higher chance of getting a crit, because you use got more tries. However when you reach the tenth 1 recipe the 10 is cheaper, because you need 30 components total compared to 25. Now if we factor in the 5% chance of getting a crit we get 0.95% up 10 we get roughly a 60% chance that you won't get a crit. For gift of mastery you need 250. so 25 times ten which is 0.95 up 25. That's a roughly 28% chance you won't get a crit. now if we compare them in terms of the entire stack. For 1 we know that 5% of the stack will be crits so 250*0.05 is 12.5. so we need 3 crits total. so my idea would be go for 1 recipe til you got 3 crits then switch to 10 recipe this way you save the most components.