No more so than other industry and will change on your location and main employer in your area. I have lot of fishermen because that big industry here. I doubt it be high demand in down town Toronto.
If you live next door to school, then it be higher demand. This is geography
It don't matter what reasonable. It matter what people willing to pay and what you need to pay your bills.What kind of increase would be reasonable....
So if you give Summer off, that is 10 week.
When you say Christmas and March Break for free, not clear if you mean open or closed but since it free, Christmas is 2 week and March Break 1 week so altogether that mean 13 week a year no income. Quarter of the year no income.
If you plan to charge more then you have to charge enough to cover 13 week no income.
$35 a day = $175 a week. x 52 week a year = $9,100 from one FT place open year round
So to have same income but not open summer and to be "free" March Break & Christmas,
$9,100 / 39 weeks open a year / 5 days a week = $46.66 a day needed to have similar income.
If you think you can consistently fill places based on teacher as little point having summer off for some and not others, then you need to be ale to charge $46.66 a day for places.