The remaining 8 sets of prices: 600×0.8×0.85×8-400×8=64 yuan.

Profit of the previous 100 set: 600× 0.8×100-400×100 = 8,000 yuan.

After-sale profit: 8000+64=8064 (RMB)

A: The store * * * made a profit of 8064 yuan.