(* Nash Equilibrium *)



draw[k_] := Flatten[{k Random[Real, {1, 10}],

      3/4 Table[Random[Real, {1, 10}], {3}]}]

x1 = Function[x, x[[1]] == 1]



Function[x, x\[LeftDoubleBracket]1\[RightDoubleBracket] == 1]

payoff[k_] := ((1 - k) Apply[Plus, Transpose[Select[

                Table[FirstPrice[draw[k]], {500}], x1]][[2]]]/k)

payoff[.85]

ListPlot[Table[{k, payoff[k]}, {k, .60, .80, .05}], PlotJoined -> True, 

  AxesLabel -> {"Payoff", "Proportion"}]