One of the possibilities is that the board do believe its a...

One of the possibilities is that the board do believe its a cheap offer, but if no-one were to make a counter offer and the valuation report by an expert comes out and also says the offer is fair then its hard to argue the offer isn't fair (even if shareholders don't like that situation). If the Essential board are playing this game, I'd have expected a quarterly that dropped a whole pile of not very subtle hints as to why a higher value may be sensible. That didn't happen.

Another possibility is recognising the board are privy good estimates of the likely capex cost and how the off-take bids were shaping up. This combination may not have been delivering a pathway that would make development of Cade easy. It would be a surprising situation if there was limited interest on good terms but it may have happened. Perhaps the off-take market doesn't yet have confidence that a prices will stay sufficiently high for a smaller resource requiring DMS plus flotation to get off the ground. Its only when the scoping study gets released that shareholders will get a good idea of the capex side of this equation. Given what happened at LTR I'd suggest the scoping study capex estimate has recently had a large increase in the capex cost from the combination of inflation, tight contractor market resources and increased contingencies. The board will look stupid if they put out an absolutely fantastic, low-risk scoping study, so expect lots of proviso's and risk statements. Cynically, part of the extra time may be re-writing elements of the scoping report to match their current view that the takeover should be accepted.

One of the difficulties for a competing bid is that its a lot of time and expense if you don't win. Clearly Tianqi Lithium Energy Australia Pty Ltd have the cash resources from current Greenbushes profitability to pay any amount they choose. They effectively have unlimited pockets. If they really want Essential, there is a strong possibility that they would simply over-bid any competitor bid. Any competitor bidding would know this. It means there is an increased chance any bid would be helping Essential shareholders but losing money for their own shareholders. If they are a market player potentially buying from TLEA, they are also annoying one of the largest lithium suppliers in the market (most spod is supplied on contracts not through a robust secondary market). Avoiding annoying TLEA may prevent any OEM/battery maker bidding. This narrows the field of potential bidders.

At the moment I'd suggest the primary avenue towards a higher payment is the independent expert coming up with not just a higher recommended value, but also keeping the bottom end of that valuation range above 50c. That would be a brave call when the market clearly valued ESS well below that before the bid.