The PRO EDU PRO Plan's prices will remain constant as long as the membership does not lapse.
Shortcuts: Jump straight to what you're looking for.
PRO EDU PRO PLAN MEMBERSHIP
Will My PRO Plan Price Increase When It Renews?
All PRO PLAN members are locked into the rate/price they signed up at, and this cost will not increase for them as long as they are active members.
If the membership is canceled for a period of time and renewed at a future date, price increases will apply.
Check current pricing at https://proedu.com/collections/pro-plan-membership-options-pricing