I started with the low thinking it'd be enough then upgraded to Pro (I think at that point they'd added the plant editor to Pro)

In hindsight, I should have gone 4 Pro to 5 Infinite.  It would have saved me money.

Talking of....money is an issue for me but I have the 'luxury' of being a vendor and had been squirreling bits of my earnings away since the last upgrade specifically to pay for the next one because I knew when it came out - I'd want it.
I'm doing the same thing now for 8 

Gill