Your assuming they don't suffer the receding horizons problem. It seem fairly clear that we are past peak net energy as energy declines everything including energy extraction becomes increasingly more expensive. From what I've seen costs seem to be increasing inline with price with no net increase in profits. If they are not profitable now they won't be at any price.

From now on out price increases simply will not change the net profitability of unconventional natural gas extraction or extreme oil plays for that matter.
Also because of the short lifetime of shale plays and the need for ever more rigs they basically have to pay current energy prices esp for things like pipelines to service the newer shale plays. They cannot depend on long lasting older conventional plays to create large profits.
The current high profits for oil and gas companies can readily be attributed to older fields and infrastructure put into production when oil and gas was cheap.

In fact the shale plays are probably our canary in the coal mine for detecting the EROEI cliff and will be the first ones over it as exploding costs make them unprofitable at any price. If you think that some magic price point suddenly makes things better then you don't understand the EROEI cliff.