Assuming these quotes are from a dealer, $600 for the timing belt/water pump
sounds competitive with other Honda dealers. You might do a couple hundred
dollars better at a specialized but independent Honda (preferably) or import
car shop.

What exactly does the tune-up include? At a minimum, I would expect:
new spark plugs (but how old are yours?)
new air filter (but again, how old is yours?)

Maybe:
New fuel filter
New ignition wires
New distributor cap
New distributor rotor
Timing check (pffft; if you've seen no problems)

My impression is that tune-ups at dealerships are ripoffs. The labor is
minimal. They do more than is needed for the tune-up. You'd probably save a
hundred bucks by buying the parts yourself and then having your local
independent mechanic install them.

Check your owner's manual to see exactly what is due.

I was just speaking with my dealership and I was quoted $580.00 including
taxes for changing the timing belt. An additional ½ hour of labour and
$75.00 for the water pump if I chose to replace that at the same time. I
always have replaced both at the same time in the past.

Brian

For the actual work involved to do the job, all of the prices I have seen in
this thread are obscene. The first time I did a timing belt/water pump
replacement, in my driveway, it took me a total of 5 hours. When I do it
again, I'm sure it will be about 3 hours - or less. This is with all hand
tools, except for an electric impact I use only for the crankshaft. You can
be sure that an experienced mechanic, using a lift and air tools, can beat
my time by a LOT!! The problem is the bloated flat rate time assigned to the
job, as well as the overpriced parts. I realize that they have to make a
living too, but give us all a break!

Acura sends me coupons occasionally quoting $250 for timing belt change,no
mention of water pump.

First, it depends where you are.  Automotive hourly rates vary by region.

That said, $600 for a timing belt and water pump replacement sounds
reasonable as does $235 for the "tune-up", depending upon what is
actually being done at "tune-up" time.   Up until the early 1970s a
basic tune-up was pretty well defined as new plugs, new points, new
condenser, set dwell, set timing, set mixture and possibly adjust the
valves if needed.  Add on items in a "major tune-up" would generally be
the cap & rotor, PCV valve, fuel filter and air filter.

Today there is really nothing standard about a "tune-up" except that
generally it includes new spark plugs.

Yet another variable is what kind of spark plugs are used.  Basic ones
retail for around $1 each today.  Fancy Iridium plugs can be $10 each or
more.   You want to be sure to be getting plugs at least as good as what
the factory originally installed.

Finally, if this is a shop you have been using for a long time and have
come to know and trust, then you are probably dealing with reasonable
folks.  Beware looking for the best price on these kinds of services.
Substandard parts, shoddy labor, etc. are all possibilities when dealing
with second class service establishments.

John