The Volvo evap kit consists of a new evaporator, accumulator, pollen air filter and blower motor "dust" restrictor BUT it'll cost over $300 just for the parts and you're looking at "around" $1,100 installed (give or take a few bucks depending on labor rate in your area).
Whoever said there's an in-expensive Volvo kit that will cheaply cure a leaking evap is simply full of it. The labor for the Volvo evap kit is a time consuming ordeal, it's the evap plus accumulator and maybe even a hose if it's siezed to the accumulator too (happens sometimes, another $100 too).