Lease rates do vary very widely (to the extent that it can be worthwhile to send the aircraft back and lease another from someone else). I think you have your comma in the wrong place in your example, but I think you meant 1% of purchase cost per month, which is a good "rough" average. This would mean that over an 8 year period you would pay pretty much the purchase price, which with financng etc is what you might expect at current interest rates.
Most leases have at least some aspect of their costs dependent on the number of flying hours and/or cycles as well, as this impacts on the depreciation and what the aircraft might be worth at the end of the lease. As we are talking very round figures stick on another 0.0001% of the original purchase price per flying hour as well.