“Would using BIAB via a laptop at a gig provide a better quality track than a rendered WAV file?”

As the Jazzman said, there would be no difference. Laptops are very cheap these days, although you would have to stretch your $200 limit to get one. With what you have invested in the Bose system, I wouldn't skimp on the playback device.

We use a laptop with a little free program – “Digital Fake Book”, which allows you to create set lists and start/stop/advance songs with one keystroke. It also lets you enter the lyrics/cues for each song.

http://mike-warren.net/dfbhelp/

I would avoid using the 1/8” output from the laptop, and instead, get one of these:

http://www.amazon.com/Peavey-USBP-USB-Audio-Interface/dp/B004A4PSEU/ref=sr_1_1?ie=UTF8&qid=1424697083&sr=8-1&keywords=peavey+usb-p

It makes a big difference.

Hope this helps a bit.


Regards,

Bob