It is usually better to sort out your claim with the other driver by negotiation rather than by going to court. Going to court may cost more money and is often very stressful.
Even if you go to court and win, the other person cannot be forced to pay more than they can reasonably afford. If the other person is not employed and has no assets, it may be very difficult to recover the money owed to you.
In making the decision as to whether to take the other driver to court you need to consider the financial position of the other person. If the other person is offering part payment or payment by installments it may be better to accept this rather than go to court. You may have to accept a smaller amount of money than you expected to get the other party to pay.
If an agreement is reached on settlement it should be recorded in writing and signed by the person or people agreeing to pay.
You can start by offering a figure 10% or 20% higher and come down later if you want. For example, if you are advised that the other driver will ultimately be 50% liable, you may suggest they are 60% or 70% liable.