Age of Ballast - how much of an issue?

Today I was offered a Lumii 600w Duel Spectrum ballast with reflector and 600w Sylvania HPS bulb (plus 2 unused Sylvania HPS 600w bulbs and a part ballast - that needs the cable and bulb holder to complete it - it already has the electric cable and power unit/ballast). I was offered it all at a very reasonable price. I saw photographs of it all, including one of it working. The seller has a fantastic reputation and is eager to be helpful. The only problem I can see is that the ballast was assembled in 2003. Tomorrow I must buy or not buy - any advice about this is needed quickly because my gut feeling is to buy.

I have a old street light ballast I converted to a grow light in 2000 that's still going strong. Is there a cord on the reflector?

There's a long white cord between ballast and bulb holder/reflector. A black cable from ballast to plug. The bulbs were £20 each and I was offered the lot for less than £70 - with postage and everything. It's on e-bay

i can get a new 600w hps ballast, bulb and reflector for £75 in my local growshop.

not a great deal imo

£55 is the cheapest I found. They're available everywhere but they are super- low budget. AND you'd still need a spare bulb. This has 3 Sylvania 600w bulbs (2 brand new) - they sell for a minimum of £20. PLUS most of a 2nd ballast. You need a second bulb, when you grow. If the bulb breaks at 6pm on a Saturday it could be 42 hours before a replacement can start working. Longer if you have commitments.