I was just thinking about this and thought it would be interesting to see what other people think (maybe it is the huge Powerball lottery jackpot up for grabs in the US). If money were not really a major concern, would you go for (or recommend) the highest spec (or close) even if the intended use perhaps didn't absolutely require it?
This is pretty much what Apple want you to do. The soldered-in components, and the peculiar spec ranges (16GB / 64GB) are designed to give you a dose of the FUDs and encourage you to bump your spec at purchase time. This may have you buying RAM or SSD capacity at 2016 prices, while not actually needing them until they're worth half as much in 2018. And its difficult to recommend resisting the temptation because the OSes are bloating significantly these days.