What is “too low” of a offer on a home in todays market?

[Juan Zamora]

I recently made a offer to a home that needed a little more then TLC. Besides painting, property needed whole new flooring, updated appliances, some cabinets repair, AC unit is on its last leg, water heater almost 15 years old, and whole lot of cosmetics like windows, old plumbing and the yard front and back completely neglected. I submitted a 25% offer off the listing price. My realtor told me the following Monday that they responded with “Seller was insulted by the offering and will not be countering”. 
can I get some advice on what is a low offer? Is 25% too low? Is 15%? 

Thanks