Salesman Ridder Problem on Five Thirty Eight

riddler.py

#!/usr/bin/python
from itertools import permutations
from math import e, ceil   

cutoff = int(ceil(5. / e)) # for verbosity - it's 2 

def solve(left, best):
  for remaining in left:
     if remaining < best:
        return remaining               
  return left[-1] # Forced to take the last offer

paid = 0  
for seq in permutations('01234'):
  offers = map(int, seq)
  paid += solve(offers[cutoff:], min(offers[:cutoff]))

print paid / 120.

(Outputs 1.2).