The telecom regulator's proposed auction starting price for radio waves is exorbitant compared with what carriers in the West have paid in recent bids, an ET analysis using the average revenue per user (ARPU) data shows. The Telecom Regulatory Authority of India's proposed spectrum prices may be close to what carriers in the US and Europe have paid in spectrum bids over the past two-three years, but when the ARPU is taken into account to work out the purchasing power parity of operators, Trai's prices on "a per unit per inhabitant basis" look steep.