People should really consider game theory when offering insane interest rates such as this. If you have enough collateral to cover the loan, then it is probably best just to sell it to get the funds you require. Of course, this can bite you in the ass if the price increases and you have to buy back at a loss, but you are offering 40%. That means in order for this to be a good decision the value of the collateral must increase above 40%, otherwise you would be better off just buying it back vs. paying that kind of interest.

Of course, the price can also go down, allowing you to buy back in with profit, so locking in a loss of 40% is clearly bad bet when you consider that possibility. But when you increase the interest to 80%, after your offer is dismissed, then it becomes pretty evident which of the two parties would be making a bad decision here.