Advanced Shipping question

Hi,

I have since a longer time a problem and I am not able to solve it! It concerns Shipping.

I offer Groundshipping, which is above a certain amount Free of charge
And i also offer priority Shipping for additional cost. Further information:

Ground Shipping: 12.90
Priority Shipping: +7.90
Amount for free Ground Shipping Russia: CHF 200.–

So it means when somebody buys stuff for 150 the following options have to be available for the client:

– Ground Shipping: 12.90
– Priority: 21.80 (Ground + 7.90)

So far everything would work! The tricky part is coming now:

When the client orders items for CH 250.– the following would has to be available to choose from:

– Free Shipping
– Priority Shipping 7.90

Step one is possible and not a problem – the problem is more that the priority shipping changes the amount and that above the minimum amount for free shipping both are still visible (but without ground shipping)

If this is not possible with woocommerce do you know several plugins where it would be possible? Anybody any experience in that?

Thanks a lot for your help and best regards from switzerland
Michael