I find that prices are relative. If you are really motivated to get something/attend an event you find a way to get the money. It the item or event is not important enough to you, then you just say it's too expensive. So there you go. If you really wanted to find $160 or however much it was, you would have made it work.
The person also needs to make up lost revenue opportunities. Would the networking opportunities and the hints and tips lead to more income than they would lose by spending time at an event? Hmm.
Again, I find it relative. If it is an event (not necessary speaking of this one in particular but events in general) some events don't warrant a time/value analysis. To be honest, I would probably drop the money to go to a mystery shopping event if they had one in a location I wanted to visit anyways whether I spent more money than the value of the knowledge because I am curious about what an event would be like + if it is someone I want to visit anyways, it creates more non-tangible value for me personally. Like I said, if someone REALLY wants to go to something, they find a way. If they just kind of "want" to go or are considering part of their "job" they may find it better to complain about entrance fees and not actually make an effort to find the money. I was actually a little surprised at how relatively cheap the event was compared to some trainings and networking events I have been to for my day job.