Saw it at a local dealer. Already have 3 AR's,so would only pick this up if it was a killer deal. Any opinions?

Well, NIB Olys go for $1000 plus at the local store.  I would say that is not bad.  

Look at it this way...the new M4 upper from Bushy sells for right at $500 and that is just a freakin' upper.  Jump on it...sell it locally.  Make some dough.

The Plinker is a basic, budget model with cast upper and lower. Nothing wrong with it. Price is about right. Has A1 sights instead of A2.

From the Olympic web site:

New for 2001, for the budget minded consumer, we offer the ultimate in a no-frills, high quality AR style carbine. It is the .223 Plinker. With a suggested retail of $598.00, it is the least expensive factory new AR style carbine available, hands down! The same rifle as the PCR-5 except with A1 sights and cast upper and lower receivers. All factory new parts, no plastic parts like some other brand name "manufacturers" A terrific carbine at a terrific price. Features include:

Cast upper and lower receivers
Button rifled 4140 steel heavy barrel, 16" OAL, 1x9" twist
A1 upper & sights
Weight: 6lbs 10 ounces
Length: 34"
Accepts all standard mil-spec magazines, including
hi-caps.
Lifetime Warranty!
MSRP ONLY $598.00

Not too too bad, why not add another to the collection