There's no minimum or maximum stake, everyone stakes the same percentage. I like the idea on paper, it would create more participation. However, in reality the only thing a maximum stake would do is cause wealthy stakers to divide their coins over more nodes to circumvent the minimum.  

If you had 50k blk, and the maximum was 1k, then you would simply run 5 raspberry pi's  each with 10k and it would be the same as staking 50k.  

I hope that makes sense.