Given the speakers' condition, I wouldn't pay more than $150 or so for this one. (Rebuilding both speakers will add another $150 or so to your total purchase price, or at least it has for me.) These mid '70s 215 cabs pop up from time to time so you should be choosy.
A year ago I found a previous-generation 215S cabinet (with center ports rather than side) in excellent cosmetic condition - just need some cleanup - but the speakers were tired. Paid $250, which is on the high end, but I'd been looking for years and the older cabs are harder to find. Now it's the perfect twin for the one I bought new in 1971.
Oh, I didn't mention that I'm from Italy, and these cabinets here definitely don't pop up from time to time! It's actually the first one I see "live" in my life!!! I don't know...if I don't grab this one I'll probably never see another!!!
Anyway, the day my friend told me "I have a Sunn cabinet from 1968 that I'm probably going to sell", I thought it was a 200S (whose head I'm looking for as well!), and I was really anxious to see it. When he brought it to me, I saw that it wasn't really like I expected, so I started getting infos on internet, and when I found out that it was a mid 70s model loaded with cheap (and beaten) transducer speakers I was rather disappointed. Speakers have also been rewired, so now it's not 4 ohm but 16 ohm, and that's why it doesn't push like it should!
BUT it sounds nice anyway, plus it looks really cool, especially with the Kustom head on top, so if the price is low, I would probably go for it anyway!
Of course I would be so much happier if it was a 200S!!! ...I like those cabinets so much!!!!