I have to agree with this post in its entirety.I'm not being a gear snob. Players come here all the time trying to find a much cheaper way to get around getting a bass amp. It never really seems to work out for them, and they just end up spending even more money because their workaround idea didn't do what they wanted it to do.
A PA is certainly a viable option, but is not going to be cheaper than buying a standalone bass amp and give the same sound/volume.