Would like to buy but still at the prices maybe S8 will be less in cost or will have a better ratio at power used.
You could say that about any batch. At some point you've got to buy or you're always going to be waiting.
While I totally agree with this, sometimes its better to wait it out a little. It does seem like the batch 8 use less chips and squeeze more out of the chips, potentially leaving less headroom for overclocking/underclocking and such. I think Bitmain will lower the BTC to Ghs cost ratio soon because of relentless diff increases and the halving.
Its always gonna be a gamble either way.