I'm starting to get lots of gear with sockets and gems to insert into said sockets. I know you can remove the gems but how much does it cost? I assume it's based on something like the cost of the gear and gem, but I'd rather know roughly how much it'll run me before I go and blow all my money playing musical gems in my low level gear.
I've tested the removal of each different kind of gem from weapons, chest armor, and amulets. As far as I can tell, what you're removing the gem from doesn't matter at all. Additionally, removing multiple gems from a single item is just the sum of the cost of removing each gem individually. Thus, all that you really need is the cost of removing each quality of gem, which are as follows:
- Chipped: 200
- Flawed: 302
- Regular: 420
- Flawless: 528
- Perfect: 648
- Radiant: 780
- Square: 1140
- Flawless Square: 1560
- Perfect Square: 2195
- Radiant Square: 2850
- Star: ?
- Flawless Star: ?
- Perfect Star: ?
- Radiant Star: ?
It's not even close to linear - see this attempt at a linear regression. I suspect the prices will continue to grow at an alarming rate - removing a Radiant Star from something might be more expensive than just scrapping whatever it is in and buying another socketed item!
As others have mentioned, if you take apart an item for salvage, any gems within it are returned to you for free.
If you don't actually need the item again you can salvage it to return the gem to you as well as give you materials.
Judging by the costs that Ian posted it may actually be worthwhile when you are dealing with Radiant Stars.
I believe it is based on the level of the item. It starts out around 100 gold when you first get access to him. I currently have level 25-30 gear with flawless gems in them. Unsocketting costs about 300-400 gold. That's quite cheap relative to the other craftsmen costs.