I just went through some early Registry mags. No price was listed by Borla or any vendors, with "Call for club price". I seem to recall a street price just under a grand. That was a LOT back then, the "Million Mile Warranty" (!) nonwithstanding. And guys coming from the performance car arena (Mustangs, Camaros) knew that the 32 hp claim for just a catback was bogus.
I didn't look that far forward, but I don't recall the first good y-pipe coming out until maybe 94-ish? By then, there were other exhaust options, including the SHO Shop catback that was rolled out about the same time as the y-pipe. Doug Mellum came out with his y-pipe around the same time.