Looks like not so profitable buy a node.

1250 rewards once in a 3 month, this is about 417TNT per month.
1TNT~$0,22 now, so it will be  ~$92 per month ->x12=$1100 per year.
But you should have 5000TNT always on a wallet ~5000x0,22=$1100.
So, only after 1 full year(!) you will begin make profit.
Also I didn't calculate hosting price here. This is additional ~$10-20 per month.

p.s. Another problem it's too much nodes for rewards - 4000 nodes online now and will be 5000 in near future and more... Rewards in a lotto system, so more nodes, less chances to get a reward.