What would cause the need to replace the stabilizer links and bushings
on a 1999 Dodge minivan with only 22,000 miles on it?

Why were they being replaced (worn or cracked) Who is doin' the
replacin'?  How much is it going to cost?

We don't know why they are being replaced.  My husband thinks the
service dept at our car dealership said they are worn.  He took van in
for an oil change.  We have free oil changes to settle a complaint we
had with them on another problem.  They suggested that Stabilizer
Links and Bushings be replaced. Cost will be over $250.00 by Thomas
Dodge of Orland Park.

Okay, now I understand.  The free oil change is a way to get your car
on the rack to try and find things wrong.  And guess what, they did!!

Ask to take a look at the worn bushings.  If they look okay, then tell
the dealer that you can't afford it.  If, on the other hand, the
bushing are missing or the stabilizer is really loose then have them
replaced.  What I mean by loose is when you hang off the thing it
moves all around.  It should be a tight fit.

If it was me, and I had a car with 22,000 miles on it - I tell them to
forget it if the bushing is there worn or not. (without even looking
at it)

First take the car to a different Mechanic. 
A vehicle with only 22000 miles on it should not need the bushings and
stabalizer links changed, unless you do most of your driving on very
rough roads, or the parts had been bad to begain with.

Thanks for all your comments.  Now I must get my husband to act on
them.  I, also, suggested a different mechanic, etc.  Thanks again.

DEFINITELY take it to another mechanic for another opinion.
As stated above, it looks like it is their way to get your van on
their rack for some "needed work".
If you let the first shop do the work, I'd make sure I was there to
watch and retrieve the "broken" "worn" parts.
Just my 2 cents worth...
thenunz