Way to risky to buy the upgrade kit as the price of BTC continues to tank.
Not to mention you are throwing away 105-110~GH/s@1W/GHs per ant that you upgrade if you were under-volting. So for 0,46BT what you get is
a 350GH/s@250W upgrade compared to just keeping the S1, might as well just buy a S3+ instead.