I am working for a Japanese OEM and had discussion with an owner of one of our franchisees. He was interested in renovation of his store facility. He might get a financial support from us if he satisfies our requirements designed for stepping up our brand image. While we are still not on a stage of decision to go or no go, the owner was trying to minimize the cost of renovation by asking for exceptions of our requirements. We proposed him to buy the other nearest franchisee store, whose performance was awful. If he buys and closes that store, he can expect more customers coming. Our proposal was completely surprise to them, since they were trying to save cost. However, our proposal makes sense because the cost of buying franchise is supposed to be much less than that of renovation. In addition, the return from the investment will be better. この表現は自然ですか？

Just some small mistakes so I've corrected them and revised it!

I am working for a Japanese OEM and had a discussion with an owner of one of our franchisees. He is interested in renovating his store. He may receive financial support from us if he satisfies our requirements, by promoting our brand. While we are still deciding on an agreement, the owner is trying to minimize the cost of renovation by asking for exceptions to our requirements. We proposed to him to buy the other nearest franchisee store, whose performance was awful. If he buys and closes that store, he can expect more customers to come. Our proposal was completely surprising to him since they were trying to minimise their costs. Our proposal is beneficial for both of us, as the cost of buying the franchise is much less than that of renovation, and they will also promote our brand. Thus, our proposal is justifiable and supports both parties/companies, and overall the investment will be effective.