(This is just for interest, not any sort of rigorous analysis or...

(This is just for interest, not any sort of rigorous analysis or valuation, and please let me know if there are any really big mistakes in the maths or info and I will asks mods to remove.)
Part of the reason sunshine gas's shares went for nearly $3 was because they had fewer shares on issue (~310 million for Sunshine, around 1,100 million for Comt Ridge). To me, it would make more sense to look at market cap than share price.

Comparing Sunshine Gas with Comet Ridge:

		2P (PJ)	3P (PJ)	Market Cap (Million $)
1	Comet Ridge	195	411	221
2	Sunshine Gas	469	1097	1,200 (adjusted*)
3	Ratio	2.4	2.6	5.4

So based on Ps, Sunshine were around 2.5 times the size of Comet Ridge, but were valued (at takeover) at around 5.4 times as much. For the market cap ratio to be consistent with the reserves ratios, Comet Ridge's value would need to increase to around $480million, or around 2.2 times what it is now, giving a share price of 44c (a little over @Autosime's estimate, but not miles off).

While Comet Ridge do have quite a bit of 2C/3C, I believe Sunshine would have had that too (They had significant acreage - 30,000km², and I think they sold Polaris before certifying any reserves, so there would have presumably been some Cs associated).

There are a bunch of other differences that make any comparison difficult. Sunshine were targetting pretty low hanging fruit (simpler wells/cheaper/less risk), but CSG was still in it's infancy (more expensive/more risk), and the world is a different place now compared to 2008!

As always, don't trust people on the internet (i.e. me) and DYOR.

Sources:
https://announcements.asx.com.au/asxpdf/20080820/pdf/31bsysfxpqqth1.pdf
https://cdn-api.markitdigital.com/apiman-gateway/ASX/asx-research/1.0/file/2924-02799509-2A1519554*Takeover value of $830 million adjusted to 2024: https://www.amortization.org/inflation/amount.php?year=2008&amount=830000000&to=2024