Heyz, got back my car and it's not bad at all. The ride seems to be much better now, but they only gave me a 6 months warranty.
I am using H&R sport spring, that's why my original suspension wear out after about a year. My ride was super bumpy before I rebuild the suspension. Now feel so much better. Gonna test it more to find out.
His price is about the same for every car, he told me even for the Mitsubishi Airtrek to rebuild the suspension is around 1.3-1.4k. But the original suspension for Airtrek will cost more than 2k. The adjustable should be around 2k range.