Well, Yes if you machine support remote price changing. click here for more details.
But, most machines don't support that. So, When you create or update a coil record, you may find out the price of the coil also can be changed. But it will NOT update price on your machine.
When next time machine report a DEX, the coil price will be updated by the real machine coil prices.
For most machines without remote price changing function, best way to change coil price is change it on your machine. and then, after next report, you will see the price changed on our website too.