I'd get the 1.9 deal anytime, if it's so good I end up using it more than a year I'll happily pay twice the lifetime price in the end.
If it's like 99% other products that offer bulk deals, I don't know such a long time ahead whether I'll end up using it that much. The expectation of savings by taking the "worse" short-term deal is higher than taking the supposed advantageous lifetime/bulk deal in my case.