Doing it yourself? And correctly? With an intercooler?
Say 2800 in bare parts, $3-500 in miscellaneous services and nickel/dime [censored]. No tuning.
If you are carefull, don't care about using slightly used parts and are creative you could conceivably do everything within $2500 and you do all the labor. Knowing what I know now I could anyway.
If you aren't smart and experienced (and believing a $600 quote makes me wonder here

) and therefore need help with the labor and design, then you can easily tack on another $1000. If someone does it, Figure $5000 if you source the parts and they do the labor....and they like you.