Hi,
I’ve had Biab from the day it became available . Don’t use it a great deal, but I have still kept it updated over the years.

The main difference in pricing is to do with the audio tracks and other add ons. The basic version only has a few. Depends whether you think you will use them.

For many years I didn’t bother with them, because I was only using the midi styles not the audio styles. I was creating user styles for my keyboards from biab styles.

For songs , the audio styles sound good, the midi styles are more basic.

Biab does have a soft synth sound source, but you can also midi your Pa4x to it and use Pa4x sounds for midi tracks

Best part, if it’s not for you, they have a 30 day money back, according to website.

The forum is very helpful , and pg are great to deal with.

https://www.pgmusic.com/bbwin.htm