Considering the current dilemma with low inventory at most dealerships, discounts are tougher to come by than normal. On the other end of the transaction, trade in values are higher than normal though.
May sound stupid but you should spend what feels right in your gut balanced in concert with your financial realities and the condition and options on the car. I had to stretch some, certainly a 987.2 Boxster S would have been plenty. None are investments except the models that sell out before production and the rest to the whims of collectors. Keeping one in superb condition to maintain it's resale is hugely fun to some of us, more than that it makes my upcoming trip something to look forward to in a ready machine.