That does sound suspiciously low for a price. Price the stuff out on AM and then ask him exactly WHY it is so cheap. I'd verify its actually Magnaflow stuff he's putting on there too at that price...
As for Magnaflow itself, yes it is a deep non-raspy tone. Its mild at idle but you still know its aftermarket. Its mild off idle and when you punch it it'll really start to open up to a legit scream at redline but is not raspy.
2000 Mustang GT Steeda #0048
Just because I give you advice, doesn't mean I know more than you. Its just means I've done more stupid ****.