I bought JD starting fluid here last month , the current price localy is now A$7.80/can , so 7 cans would run A$54.60 . So for 2.5L it would cost approx A$114.70 via JD starting fluid, so depends on what grade he gets as to which will be cheaper.
For me haveing a large JD agent close by its much easier to use the JD fluid(it gets cold here), but theres a lot of JD agents that dont carry the starting fluid here in oz due to our temps, and the starting fluids sold in our auto parts stores is only 25% or less either content.
Stewart