My take on this is if you've exhausted all your funds into the best turbo, a header, exhaust, intercooler, fuel delivery, and head work, then yes spend some on a cam.
Agressive? as in overlap or lift?
I've seen many make the mistake of overcamming a good engine (turbo and N/A) in anticipation of big HP.
Considering that the Ford A237 is worth about $600 up here and that's about as agressive a profile as I would run on my street turbo.
A special grind with rollers can run upwards of $1000 and that compared to a good Turbo and my RR at -4 is not gonna convince me to shell out.
Also considering my street car seldom see's redline of 6000 my cam does the job.
But I will give you the benefit of the doubt, as always, it depends on the application.
Ive got a volvo intercooler, la3 computer, forged valves, 3" VAM, and K&N filter, I dont really know where to go after that thats why i was asking about the cam, I also am doin Some exhaust work right now