In my own experience of crafting level 60 yellow weapons, I have had a mixture of success rates and all I can really say is that 'it's totally random'.
However here are my own personal experience with the different yellows I've attempted:
- 60 Bodor Sword (1 hander): Made about 8 oranges, and made the yellow after the first 3. I only used bliss on the yellow. ~1300g. I was fortunate and got 3 slots an Accuracy prefix on the first go. Did this using my guardian sprite. Had another accuracy orange Bodor which I also use. Made more than I spent making the swords from the large number of Ancient wood I had left over.
- 60 Siropas sword (2 hander): Very poor luck, I had about 5 oranges and tried using bliss in order to make atleast one of them yellow. The amount of times that the sprite kept bringing them back was nice, and I appreciated that. However after about ~20 or so attempts and a seriously lack of resources in the auction house and any that I could gather, I gave up. Spent ~3500g with no luck. This was because I was too lazy to gather the mats myself and bought most of them from the auction house.
- 60 Bahado's Hero Gun (Ranged weapon): Very nice, by this point I was not in the mood for making anymore yellow weapons, but hearing about the good DPS this could provide I decided to make it. Attempted it and made it with two oranges. < 500g all up.
I would like to make the following comments concerning 60 yellows:
- The mats for them are not commonly in auction house, so you will need to find them really cheap or be able to gather them yourself. Otherwise you may have to pay a handsome amount from someone to gather them for you.
- WCM bosses do not drop these mats in generous amounts; if you are able to solo them be prepared to farm for a while.
- Do not buy the orange mats needed for the orange weapons from the AH, you'll exceed the cost of an SKB3 quite easily. You're better off gathering these even if it does take you a long time.
I conclude by saying you got two options:
1. If you have the time to look around for cheap ah prices for the mats you can't gather, and get the ones that you can gather using your sprites, you'll find the yellows are quite cheap to make.
2. If you really just want the yellow, and you want it now, then don't fork out the money for the mats for one try or a few tries and pray for a miracle. You're better off with an SKB3.
EDIT: Oh yes, SKB3's are between 5.5k - 7k gold now.