Is there a facility that test cables?

Unfortunately it would probably require comparisons of say three major high end brands at different levels to properly position them. The largest selling brands are Audio Quest, Transparent, and Wire World. So, if you got a pair of each at the same cost level as yours, then you could do the comparison. Although, the problem is, that it is component dependent. But this would be a start. 
 

No, a lab thing would be of no use.

Contact audioholics. I believe the owner offers consulting and testing, but it’s not free, as I’m sure you would expect. At lest discuss it with them and see if it’s possible to test for what you are looking for. 

You would likely be disappointed if you found out the actual material cost of those "magic cables." What are "tests" going to prove?

Do yourself a favor and just use them. Convince yourself they're an improvement to your system more than the previous.

Power cable as a means of "improving" your system...that's an ugly thread topic.

Fuses and shiny, anodized,quantum kniffle generators anyone?

Thanks for the responses everyone! @chayro I might do that, t@tablejockey you are probably right; maybe I don't want to know!

dadork-

I suffer from  audio neurosis, but I at least am aware of it.

I use all Nordo$t -wall to speaker. Ridiculous at MSRP. Looks impressive to my non audio, musician friends.

Giving the builder the benefit of the doubt, you have super magnum platinum cables that indeed, make your setup "better."