I use scents for 2 purposes
1. cover up my own scent. *(as nice as it may be I don't think it helps attract fish)
2. When I am targeting fish that rely heavily on scent for finding food. *(like trout and catfish)
Berkely makes a decent trout attractor in a squeeze tube and in the past I have used other types of scents for bass and the such. *The problem is it came in a spray bottle and they *tend to leak and break open. *The downside was my care smelled for months the upside my lures and tackle were all prescented!
The expense...... I suppose they are worth it. *They cost less than one Rapala and I have tons of them that I have never caught anything on.
Life could be worse, you could be Zman or Rottal