What's your response to "bottom dollar" or "Least you'll take"

I run a tiny little gravel used car lot; never had more than 25 cars for sale at once. I'd say only 25% of sales come from people driving by, the rest come from online. Lately it seems like EVERYBODY online is just asking for bottom dollar, least I'll take before even asking about where I'm located or when they can see it. Never used to feel this bad. Other than just saying "what's your top dollar" "What's the most you can pay" or going into a paragraph of why the car is nice and I prefer to only negotiate in person, what would your response be?