Vix, I'm at about 60%, and honestly I just let it go at a certain point (specifically last December). It was very much a "grit my teeth and bear it" process. I have been trimming the ends every month or so to speed up the process from the bottom up. A huge plus in growing it out has been that I do not have skunk stripes or patches at all - my silver is quite shot through and evenly distributed, so although it gives me more of an overall grey, it isn't as much contrast as stripes would be. I am planning to dip dye the very ends, possibly dark violet, red or black, when it's all grown out.
The money I've saved is quite an eye-opener, as is not having to worry about washing color out or having it fade, and my undamaged hair feels so much healthier. I'm also noticing a change in the colors I want to wear - although it's not so much which colors as wanting more of those colors.
You can do it! Sorry to hijack this thread!