Impossible to know without seeing actual photos (as condition is everything), but in general, a McDermott C-11 cue is worth somewhere between $500 and $700.
One sold on eBay for $685 in 2017 (also no photos, but it was also in excellent condition).
Another pristine McDermott C11 cue sold on eBay for $650 in 2018. The listing is still on eBay but the photos are gone. It was in very good shape, just as yours appears to be (though I can't really tell from those photos). This listing had some good info on the cue...
McDermott USA C-11 Pool Cue - 1980-1984 - Rosewood Forearm, 4 Veneers
This is a McDermott C-11 pool cue made in the period of 1980 to 1984. The McDermott C and D series cues are some of the most highly sought after cues today. In 1980, McDermott launced the C Series. The C Series consisted of 21 models all displaying beautiful hardwoods, elaborate sleeve designs and intricate inlays. The cues featured nylon wraps standard; leather, cork and Irish linen was available as an option. These cues were widely known for their artistry and superb craftsmanship.
On this particular cue, McDermott started with a Rosewood forearm with four walnut-stained Birdseye Maple points, each with four with veneers of orange, black, green and black. The detailed walnut-stained Birdseye Maple butt sleeve has six pearl notched diamond-shaped inlays set in long thin Rosewood windows between elaborate rings at top and bottom. Each set of rings is black, green, black, then a thicker piece of Tulip wood, and another set of the black and green rings. The Birdseye sleeve in this cue has lots of “eyes” and character as it is highly figured and has a beautiful grain.
It is my opinion that the walnut stain on the Birdseye Maple really sets off the cue, so much better that the natural stained Maple of other C-11’s I have seen. Also, the Rosewood doesn’t seem to be as dark as some I have seen and the richness of the wood really cones out.
- Rosewood Forearm & Maple Points
- Maple Sleeve with Rosewood Windows with MOP Notched Diamonds
- Four Inlaid Veneers of Orange, Black, Green and Black
- White Implex Joint & Butt Cap
- Original Black Nylon Wrap
- Original 12.9mm Maple Shaft
There is one on eBay now, in basically brand-new condition, selling for $898 USD. It was professionally restored at McDermott Cue, and had a brand new matching shaft made. It is being sold by a very large pool cue dealer. This is obviously priced at the very high end for that cue, and the price factors in the refinish cost as well as the cost for a new shaft. It's been for sale for a while and isn't moving.
Here are some photos of the one that is currently for sale:
McDermott C11 Cue in 100% Pristine Condition with Lifetime Shaft Warranty
Vintage McDermott C-11 cue, 100% pristine unused condition. McDermott refinished butt, and new rock-hard maple shaft, pro taper. 12.50mm Tiger Everest cue tip. Brown McLizard leather wrap. 20.5 oz. Absolutely perfect. C-series cues were produced from between 1980 and 1984.