Best route for more gnarly exhaust sound

I have a 1980 Suzuki GS750, and I am not digging the farting duck sounds it makes. I'm interested in putting on a 4 into 1 exhaust, probably with no baffles, and I find kits like this for about $300 on eBay. Is that the best option to make my exhaust sound meaner? A $300 kit? If I were to take the bike to an exhaust place and have the pipes made custom, from scratch, would it be cheaper? Do you think a place that does exhaust for cars all day could do the right job for a bike? I had a 1957 Chevy done at a place nearby, using mufflers I already owned, and it cost me $80-$100 or so, 10 years ago. I guess I could go in and ask them for a quote, instead of bugging you guys. But I just thought maybe some of you have had to make this choice in the past.

Thanks!