De Arching SS Springs

How much is a fair price to have them de arched? I was told $90ea by a local company but don't know what's involved and whether or not it's worth it.

72 duster, mild 318/904 that I minitubbed years ago and never finished. I've got the bug to get this thing back on the road and it sits about 5 inches too high.

Comments welcome. Flamers welcomed as well.