Paul Kelly.
It is probable that for them to accept k3 they will require you to fill out an income/expenditure statement.
From what you write you have little free income , so I suspect on sight of your income/expenditure they will accept the k3.
Do not worry about sending it on , if you ain,t got more money then that's it .
Suggest do not get into (trading), just make one fair affordable offer.
If it is fair and they do not accept , send them nothing; that will have the effect of making them sit -up.
Keep everything in writing ,phone calls just do not work.(keep copies)
As you said, go for closure , that might mean you pushing them a bit,
But please do not be bullied .
Good Luck.