CNN image extraction to predict a continuous value
I would use the CNN to predict the model of the car and then using a list of all the car prices it's easy enough to get the price, or if you dont care about the car model just use the prices as lables
I have images of vehicles . I need to predict the price of the vehicle based on image extraction. 
What I have learnt is , I can use CNN to extract the image features but what I am not able to get is, How to predict the prices of vehicles. 
I know that the I need to train my CNN model before it predicts the price. 
I don't know how to train the model with images along with prices .
In the end what I expect is , I will input an vehicle image and I need to get price of the vehicle. 
Can any one provide the approach for this ?