Shipping method cost field bug report

Hi there,

I believe I discovered a bug in the woocommerce cost field within the shipping method form.
Steps to provoke this bug.

1. Open a shipping method
2. Set a price in the costs field: 4,9 with a comma
3. Save
4. Open the method again, price is saved and shown as 4.9 with a dot.
5. Save again without any changes
6. Open the method again and it will show the price as 49,00

If you don’t click save in step 5 but close the window on the right top corner, it will keep the 4.9.

I hope you can follow.

Thanks for checking.

Best regards
Axel