Are people really paying $50-$200/month for landing page testing and optimization? I get that there appears to be a lot of features, but seems like overkill to me.
Yes. In fact we have an agency account which costs a bit more. We use it all the time for a roster of folks who don't want to pay the monthly fee but are interested in improving conversion rates.
1% boost in conversion in a business with $100,000 annual sales = $1000, which is almost double the price of the lowest plan.