how, or where do you get it?

I only got one "main hand weapon construction kit" and i got that through the main quest story line

so will the purple crystals be ridiculesly expensive? .. or will they be average price and plus will there only be a certain amount of them, like after a certain few days will they stop selling them ? and when will this patch go into effect. Im so glad about this crystal colour thing.. it pissed me off that the purple crystal was like a level 50 rare item.

and also will you have to pay for the DC ?

Im trying to defeat Valis. (not going well and im a level higher than him) someone told me he's doable with " Interrupts" whats an Interrupt ? lol

right i sent T4 to collect lightsaber crystals through the crew skills and he returned with colour crystals. but it wont let me put them in my lightsaber, why? i have 9 green and 3 red.. is it something to do with the quantity? help please