I have a 98 F-150 with 190,00 miles. Last oil change I was told my tie Ross and away bars must be replaced. Told they must be done together and quoted $900. What should I be paying and do they have to be changed together? Thanks 
They don’t have to be replaced together.
I bet they mean the sway bar LINKS need replaced. rarely will anyone need a whole sway bar.
Tie rod ends could be purchased one at a time ( there are 4 ) BUT they’ve all seen the same punishment and alignment will need readjusted with each replacement so those are better replaced as a set ( unless you can truly prove only one or two is needed ) for a savings on labor.
OE are about $60 each unless you’re buddies with the dealer and get discounts.
AutoZone about $ 30 each.
sway bar links about $ 40 each dealer or 15 each at the Zone.
no alignment needed with sway bar work.
Maybe you can get under the truck and have someone swing the wheel from side to side a few inches while you watch and feel the tie rod ends. When they are worn they wobble noticeably and replacing them does not require re-aligning the front end. The tie rods only affect the toe, which can actually be set with 2 yard sticks.
I am often wary of mechanics who wish to scare owners into getting questionable repairs done at outrageous prices and that’s what your story sounds like. The flat rate time for replacing all 4 would be less than 2 hours and the flat rate to set the toe in is less than 1 hour. Ken Green’s numbers are right on. And if your local labor rate is <$100/hour I would think that a total estimate for all 4 would be $600 +/-.
Thanks guys. Brought the truck to a trusty mechanic. I have almost 2 inches of play and the entire front end needs work. I’m not attached to this truck enough to make these repairs, so she’s gonna get sold:(. I’ve already purchased another vehicle as she is not safe to drive until repairs are made.