should I offer asking price on used car on car gurus?

I wouldn't. Usually people publish a price that's higher than what they would sell it for. Don't low ball with your offer. You can try 15-20% under asking and the seller can counter offer. It all part of the negotiations.

Ditto. Heck NO. Those prices are negotiable and see how long it's been on the market. Then make an offer, just like tenspeed said, say 20% lower, then he (she) will counter offer. That can go back and forth many times. Then it depends on just how badly you want the car, always remember there are millions of cars for sale all over the place. But the seller never seriously expects to get full asking price. IF the car is near you,and by 'near I mean maybe 200 miles go look at it and preferably have it checked by a mechanic. If it is coast to coast, beware, please. Get the VIN and a Carfax carfax carfax, if it's a dealer demand it free, if not pay for it yourself ..$40