If the deal goes through, 6.18 ESS will get you one DVP. With ESS at $0.47, that means you will be buying DVP at $2.90. DVP trading at $3.20 means a 9.37% discount. I don't know where your 30% comes from. 9.37% discount is a good deal if you can be sure the SOA succeeds, but it essentially is the risk premium your are being given that it may not succeed.
I would have thought it was a done deal, but that was before I was made aware that 50% of holders (not their shares) need to vote for it. I have no idea what the general feeling among the ESS holders is.
ESS Price at posting:
47.0¢ Sentiment: None Disclosure: Held