Tires and Wheels problem
2007 Nissan Murano All Wheel Drive Automatic 33850 miles

I had car at dealer for routein oil change and check up via maintanence plan. I have had no problem with the car. I was told my tires are "feathering" and I need 4 new tires oh yes and a realignment too. I have had the car in for every schedueled rotation, checkup whatever and no prior mention of a problem. I do not feel any pulling. the tires look fine and have good tread. I even had the tecknition show me where they felt "feathering" and I feel nothing. If they had said they suggest an alignment I wouldn't have thought twice and would hav e had it done on the spot. But 800$ for new tires plus and alignment gave me pause for thought. I feel like they are trying to rip me off. I need more info on "feathering" and what it means. How long do I have before I really need to change the tires. Is feathering the result of tires being inadequately balanced in the past or are the wheels starting to go out of alignment.?