New member, with suspension/warranty question

I just purchased a 2015 4x4 base model double cab short bed. I'd like to put a suspension lift on it but was told it would void the warranty if I did it myself. The dealership then said they could do it for only $600, what a deal!!!. Does anyone know if this is indeed the truth or should I proceed it putting the lift/leveling kit on myself?

Thanks

 

They're going to put on a garbage $150 spacer lift on the front only... Do it yourself and do one with a little bit more quality to it.

 

yeah, just curious if anyone else has run into the "warranty" issue with the dealership.
You have any recommendations? I have done spacer brackets on my jeep in the past and never had any issues. This is what I'm looking at: http://www.suspensionconnection.com/52907.html