Personally I don't know of an easy way of achieving exactly what you want, the closest I could think of is:
Divide the weight of non-hazardous products by 1000, so 15 kg is entered as 0.015.
Multiply hazardous product by 10, so 15kg is entered as 150.
Enter the weight table as:
Non-Hazardous
0.025 - £10 (upto 25kg)
0.050 - £15 (25-50kg)
0.100 - £20 (50-100kg)
1 - £40 (100-1000kg)
11 - £75 (1,000-11,000kg)
Hazardous
250 - £20 (upto 25kg)
500 - £30 (25-50kg)
1000 - £40 (50-100kg)
10000 - £80 (100-1000kg)
200000 - £150 (1000-20,000kg)
EDIT: Just realised the above doen't work if someone orders say 1000kg non-hazardous and 1.2kg hazardous as the artificial weight would be 1kg + 12kg = 13kg = £20 which is too low, therefore the above suggestion can be ignored as it won't work, the problem being that a heavy non-hazardous order is more expensive than a lightweight hazardous order.
Divide the weight of non-hazardous products by 1000, so 15 kg is entered as 0.015.
Multiply hazardous product by 10, so 15kg is entered as 150.
Enter the weight table as:
Non-Hazardous
0.025 - £10 (upto 25kg)
0.050 - £15 (25-50kg)
0.100 - £20 (50-100kg)
1 - £40 (100-1000kg)
11 - £75 (1,000-11,000kg)
Hazardous
250 - £20 (upto 25kg)
500 - £30 (25-50kg)
1000 - £40 (50-100kg)
10000 - £80 (100-1000kg)
200000 - £150 (1000-20,000kg)
EDIT: Just realised the above doen't work if someone orders say 1000kg non-hazardous and 1.2kg hazardous as the artificial weight would be 1kg + 12kg = 13kg = £20 which is too low, therefore the above suggestion can be ignored as it won't work, the problem being that a heavy non-hazardous order is more expensive than a lightweight hazardous order.
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