1. it's not a ball bearing, it's a ball joint.
2. it provides the suspension pivot and steering pivot point.
3. it's a medium job - need to strip each wheel station down.
4. call around on price.  make sure whoever does it uses oem honda joints.
5. this is what happens if you don't replace it.
http://www.tegger.com/hondafaq/lowerballjoint/index.html
6. maybe - if you have a press or a large vise and the dies.

Hi, what is the model, year, and miles on this Honda?

Might you mean the "ball joint" below? Hondas typically have
an upper one and a lower one. The lower one most certainly
can fail catastrophically and dangerously. For an excellent
anecdotal description, see
http://www.tegger.com/hondafaq/lowerballjoint/index.html.
Scroll right down to the photos, for starters.

A ball joint may be said to be a pivot point for the
transmission of forces on the car's tires to the suspension
system (springs and shocks in particular). They have to
function while the car is turning, of course. See
http://www.carcare.org/Steering_Suspension/ball_joint.shtml
.

I rebuilt much of my 1991 Honda Civic's suspension this past
summer, but not the ball joints. While researching this, I
saw plenty of do-it-yourself reports on it. I think I could
do it myself. I consider myself a low intermediate amateur
when it comes to repairing my Honda.

Check back for reports and advice from folks who have done
this themselves.

I would not drive the car. See the link above again. Your
safety comes first; then the value of the car.

$200 does sound cheap, though. See if the guy is going to
use OEM parts or what all.

Note that this is, and should be, properly cross-posted.