Data Sufficiency

At the beginning of last yr, car dealership had 150 cars in stock,which dealership hd purchased at $20000 each. During same yr, dealership made only one purchase of cars. What is the total amount spent by dealership on cars it hd in stock at the end of last yr?
1. last yr, dealership purchased 50 cars for $18000 each.
2. last yr, total revenue from sale of cars was $180000.

Hi Mehak IMO C

This is how I approached:

We need to find, total purchase - total sale
From 1
Total purchase = 150 * 20000 + 50* 18000
Total sale = unknown
Insuff

From 2
Purchase = unknown
Sales = 180000
Insuff

Combining both we will get the ans. So C

Let me know if I am wrong.