You can not really equate labor into it if you are doing it yourself
Your time is your time, that is why you do it yourself to save the extra added cost of say the metal tech sliders plus some of us really enjoy doing it ourselves as opposed to having it done for us
Is someones diy sliders going to be just as good looking as the MT sliders maybe not, but the big question is do they perform as well.
MY sliders have taken everything I can throw at them without issue, and I am sure they perform just as well as the metal techs IMO
Mind you I bought a kit for $300, I do not count my labor because it is what I wanted to do so it is irrelevant and my labor does not cost me anything in reality because I enjoy it and got satifaction from building something that has performed well which in my book is priceless
Some people prefer the bolt on and forget about it way like most people, and others prefer doing it their way
And there is nothing wrong with that .
Its $600 that did not come out of my pocket regardless of my time spent on them.