Its great to hear of Erin's success over the last few years.
In regards to the repeat clients and the issue with wait times versus cost, why not start reserving space for readings for 'follow up' clients, so that their wait time is less, but you can still keep the overall price flat. Sort of like physicians setting aside emergency appt slots each day, they don't cost anymore, but are essential to keep established patients happy when they have an urgent issue. A new patient would not expect to get in same day, but understands that those spots are available once established.
Personally, if I was a first time client of Erin's, I would rather wait a bit longer at the same price, then stretch it further outside my budget. This may not work long term depending on how many readings Erin does after the initial one, but it might help appease both parties right now.
Just a thought...