They usually sound decent if the rest of the exhaust is stock. Once you add free flowing headers, y-pipe or test pipe they usually start to sound like crap (obnoxiously loud and loads of drone). Fitment can be slightly off but usually not too bad..

 

This one just got good reviews in another thread.

https://www.ebay.com/itm/fits-99-200...53.m1438.l2649

 

If youre willing to deal with custom work, trubendz has 2.5'' and 3'' exhaust tubing that is good quality. Youll need to supply your own muffler and resonator as well as put it all together though. If you are handy with such things or have a guy for that, its a great deal, you could get a stainless steel 2.5inch tube setup and buy your own muffler/etc for under $400. Otherwise it can add up to the point where its not really worth it (unless you have a custom design in mind, of course). I have a 3'' setup sitting in storage that Ill be getting put together when it gets a little warmer. I cant speak on how it sounds just yet but the quality of the piping itself is good.
http://www.trubendz.com/categories/t...an-maxima.html
Ofc the best option is probably to stalk the classifieds section (and i guess facebook if youre into that) and wait for someone who is selling. You might be waiting for a while though..