my phone will not turn back on, i dropped it in water, how much will it cost to get fixed

Many times (due to possible internal corrosion) liquid damages cannot be repaired, sorry.

To feel more comfortable, make an appointment and have your device inspected at an Apple Store or AASP (Apple Authorized Service Provider) among this list:--> Apple – Location Selector

After checking it out, they'll give you all the available options.

Regards