Below is an instruction that describes a task. Write a response that appropriately completes the request in English. Please answer in English.

### Instruction:
Ronald wants to make profits by re-selling some phones he bought a week ago. He bought 200 units for just $3000, and he wants to gain a third of the initial investment in profits when all units are sold. Including the profit margin, what will be the selling price for each phone?

### Response:
The profit Ronald wants is $3000 / 3 = $<<3000/3=1000>>1000, which is 30% of the initial investment.
The profit per phone sold will be $1000 / 200 phones = $<<1000/200=5>>5/phone.
Including the profit, the cost of each phone will be $3000 / 200 phones = $<<3000/200=15>>15/phone.
The final selling price will be $15/phone + $5/phone = $<<15+5=20>>20.
#### 20