With about 1 minute of thinking behind this, no, I can't see a native way of QW handling this.
This would be relatively straightforward with a custom script however.
Could you contact me with a quote for this please, shall i email my details to your email address?
Yes, send me an email when you have chance! Cheers
Is there a way of setting up pricing so if the amount is any number between
1-5 - £100 - total
6-10 £150 – total
1-5 £100 - = £500
6-10 £150 = £600