“Preachers who distribute the process of chanting the Hare Krishna Mahamantra are specifically banned from asking money for mantras. Some yogis sell mantras, and even certain sampradayas in India have basic, fixed price for diksa and mantras.
Here Srila Bhaktivinoda Thakura exposes this practice as a disqualification. Actually the Holy Name is priceless – so how can any price be attributed to it? The point is to avoid commercializing the chanting of the holy name. Nama Hatta preaching is a great opportunity for receiving the mercy of Chaitanya Mahaprabhu and spreading it to others. The reward that a devotee should aspire for is the priceless mercy of Lord Caitanya, not any mundane remuneration.
Having forbidden the asking for money for mantras, Bhaktivinoda Thakura does not restrict the acceptance of voluntary donations given in accordance with the customs of varnashrama society. Sannyasis, vanaprastas, brahmacharis, and brahmana grihastas are authorized to receive donations, which should be given voluntarily and according to the donor’s desire.
Guru-Dakshina is also authorized. Actually Bhaktivinoda Thakura makes the point that is it beneficial for the disciple, at the time of receiving the mantra, to donate to his guru.”
Courtesy: ISKCON Congregational Development Ministry