# R, 41 chars

    a=scan();b=min(a);sum(5*b+(a-b)*c(2:4,1))


Usage:

    > a=scan();b=min(a);sum(5*b+(a-b)*c(2:4,1))
    1: 4 5 4 5
    5: 
    Read 4 items
    [1] 84
    > a=scan();b=min(a);sum(5*b+(a-b)*c(2:4,1))
    1: 3 5 4 3
    5: 
    Read 4 items
    [1] 70

In the last example, `a` is vector `3 5 4 3`, `a-b` is `0 2 1 0`, which we multiply with vector `2 3 4 1` thus giving `0 6 4 0` which we add with `5*b` giving `15 21 19 15` (`5*b` being recycled for each member of the added vector, hence effectively adding `4*5*b`), which we finally sum, thus giving `70`.