Get what makes YOU feel happy. Everyone is different and as such, everyone will have different opinions.

I am going to go back to your original situation. Will you have several nice cars or would you just buy your dream car. I think it depends on several factors.

Would I give my 3 fun cars today (F430, EVT750 997 turbo, GT-R Alpha 9+) for a McLaren 720S? It is extremely doubtful. I just sold my SL-C and that thing was a blast - would I give up all 4, have some money to play with the 720S ... nope.

I would rather keep getting different cars - having a variety is a much better situation for me anyway - but again, others may disagree.

Just do what you want and what makes you happy.