You've misunderstood. You can choose what your sale price is. You may or may not clear the market (find a buyer) at that price. But, if you do, you may have to sell to the government. You choose the price but not the buyer.
Based on the parent comment, I don't think I've misunderstood
"if your property is eligible for preemption, you have to declare that you intend to sell (at the price you wish) to the city, which can then tell you that [list of options here]"
It seemed like the city has right of first refusal. If they make a counter offer you are then either obligated to accept their offer, or go to tribunal, or not sell
Paris property remains extremely expensive.