To Buy or to DIY, here is my question

Save up until you have $8K for the used pair. No way you could duplicate factory quality!

Depends on your DIY skills, how much time you have, what you want the end product to look like, and whether or not the difference in price is worth it.

BTW, A quick Google search shows me that a pair of those used should be nowhere near $8K.

I’ve heard some pretty good DIY speakers.

Most of them look like $hit, though. I’ve only ever seen one pair that was DIY that would pass the WAF, and that guy was a master cabinet maker.....so....take that for what it's worth.

1 - Ask in DIYaudio where the best builders hang out

2 - I think you are going about this aaaaaall wrong. 

Trying to compare one specific pair of speakers with a random DIY offering is bullocks10.  I say this as a dedicated DIYer, but that's no way to buy for sound quality or to guess at what the final product would be like.  This is like comparing a Nissan to some random truck based on tire brands.  How on earth do you do that?

If you DIY you should do so for the experience, and if you are just starting and want to use expensive components rely on a pre-made kit.

If you’re not proficient at designing and tweaking a crossover, I’d consider a kit that has already worked out those details. The crossover is just as critical as the drivers and the cabinet (maybe more-so because of the ability to compensate). To be right, a speaker has to be a complete and cohesive design....its far more than the individual parts. The crossover is a key element in that design that shouldn’t be under estimated. DIY can be an awesome endeavor, and can save some money, but there are a lot of unknowns about the outcome.