I still think 50 is fair. If it were "elitist" as suggested it'd be 1000 posts - 50 is not unreasonable.
About the IP thing you say making it easy to spot multiple accounts that way. Doesn't work like that. In the old days yes, these days no. If a person logs in on a mobile device, it's a different IP every time I've been told (when we were having problems with another forum). So you cannot track or rely on that. It's also way too easy these days to surf the net under a false IP. Theres websites dedicated to assisting the noob to do this. Another thing I learned whilst having trouble running another forum.
The simplest measure is to make it a higher post count.
Since the count has been bumped to 10 there's already been a few simple/spam posts going on. 10 is easily achievable. 50 is a lot of effort and not as easy to hide.