Guild Wars 2

If my understanding is correct, you can get ectos from salvaging level 68+ yellow and orange items. For armor this is straightforward enough, but for weapons you also have the option of putting 4 in the mystic forge to get an upgrade or a legendary precursor.

Does anyone know of any sensible guidelines regarding in what situations it’s better to salvage vs. combine in the forge?

Sell all rares on TP. Ectos are dropping in price each day, so for 1 rare today, you will have 1,5 ecto in 2-3 weeks.
Unless you wanna try your luck in MF, but you should have nerves for that (following ppl trying to make a precursor shows, that 95% players are NOT succesfull trying to make a money on converting rares).

I was astounded last week when I salvaged a yellow level 64 and got an ecto from it with a master salvage kit.

It’s my understanding that throwing anything level 75 rare or below into the Mystic Forge is not a good way to get a precursor, since the drop rate for those is so low.