The key fact isn't the value of the club, I'd imagine you could have it for £1 now if you wanted.
The problem is you'd be inheriting £30m of debt. Currently that debt is interest free and has no repayments as it's owed to the owners. However, if the club changes hands do you seriously expect SISU to keep those terms? Why should they?
The negotiation isn't about the value of the club, it's about the terms of repayment of those loans. SISU could very easily cripple the club if they wanted, but the club going into liquidation would do them no good. So they need to agree loan terms that give them a return on investment without crippling repayments. And that's a tough negotiation.
Hoffman's initial bid wanted to pay nothing until we got promoted, and if that didn't happen in 3 years then write off the debt. To be fair to SISU that's an awful deal and they'd have been crazy to go for it.
As I've stated before, as a pure guess, I'd imagine they want an initial amount up front then a payment plan in place over the next 5-10 years. What those amounts are is the sticking point.