Theres you, a van and a leasing company. Only one person is paying money in (you) They have offices, staff, wages etc.to pay for. Somebody is paying for it at the end of the day
Work the rest out for yourself. You pay the same as if you are buying the van but three years down the line they take it back leaving you with nothing. Its absolutely impossible for it to be a better deal, no matter how they try to present it. You are paying their wages.