Tier 4, $75 per month, includes everything from Tiers 1–3 plus mentored study (including practices) of a particular topic in the Teachings (e.g., from https://wahiduddin.net/mv2/index.htm), which might include the loan of some very-expensive and long-out-of-print books. You will receive a personal birthday gift from Hafizullah (maybe a calligraphy), so be sure that we have your address and birthday.