I'm thousands of miles away from SoCal, but have you checked in beauty supply shops for hair? They often stock long, colorful extensions around here, but I couldn't say whether a grey-lavender would be something they'd carry. Your best bet, if you want to do it on the cheap without buying online, is probably to get some white or other pale-colored nylon and dye it yourself. (I don't recommend trying to dye poly hair if you've never done it before. It's more finicky to work with.)
As for rerooting tools, Michaels definitely sells the
components for rerooting tools, but you won't find them pre-made. If you have a hard time snipping your own needles, I feel you!
My only advice there is to make friends with someone who has strong hands and ask them to do a bunch at once.