Is $8,000 to replace the whole deck a fair price?

I received a quote for $8k to replace the entire deck. I'm wondering if it can be repaired instead, perhaps by just replacing the stairs and restaining, or if a full replacement is necessary due to the damage. I'm not sure how old the deck is, but it could be original to the house, making it about 25 years old. It hasn't been restained in at least 8 years. The stairs definitely need to be replaced as they are not up to code and have nails popping out. The rest of the deck seems sturdy, just ugly. I'm unsure if I can trust a contractor to be honest about whether a full replacement is truly needed.