The thing is that at the conference centers set-up to host these kinds of events, that is what the rooms cost. In any metropolitan area, that is what rooms cost.

I’d also like to know how the author arrived at that amount ($194). Did he call the front desk and ask what the rate was?

Often there is a discount given to groups. It could have been a $250/night room they paid $194. Or it could have been a $194 (strange rate) room they actually paid $160 for.