There are 48 states in American land. 250/48 <6!!! How many cities there are? thousands!!!! 250 is a small number. Before your service is ready, no one will buy your car (you may also lead to legal matters).
If you sell a car for 10K USD, you can sell the same price in China. When you sell it in US, what profit you can make?
Korea does not have a huge population as China so they have to sell KIA in the states.
In addtion, you brought up a point "维修的费用要多少". Therefore, 30% saving from sale price is not very attractive if the total price is around 10K (the saving is only 3K).
Therefore, it is no "future" for in-expensive cars in current market (where echo/corolla, civic, focus, and neon dominate). If you can save 30% on a mercedes-class car, that is a lot. Beside, the 维修的费用 for Luxury automobiles is very expensive.
If you start pernetrate the low-end market, I am sure Toyota/Honda/Ford will come up a strategy to sell cars in this category for less as long as they can make profit from other cars. Those competitors all have cars in different categories.
Only if you can compete with luxury cars, you can enter US markets. Only competing the price at 10K is no future especially when you don't have cars in other categories.
It is just an advertisement and no real sale woule happen in 10 years.