Does this coin look like a clad coin to you? Seller makes no mention in the description. Seleukid Empire, Demetrios II Nikator AR Didrachm. Tyre, dated SE 184 = 129/8 BC. Diademed and draped bust right / [BAΣIΛEΩΣ] ΔHMHTPIOY, eagle standing left on prow left, with palm frond behind; to left, club surmounted by A PE in two lines, A and monogram above ∆ΠP (date) to right, monogram between legs. SC 2196.2c; HGC 9, 1125; DCA 232. 14.07g, 27mm, 12h. Good Very Fine.
I think clad is a term more used for modern coins plus it means there are many metal layers present in the coin intentionally for circulation. This is definitely a fourree as @frankjg mentioned. A fourree has a bronze/copper core with a silver outer layer and is meant for ancient counterfeiting.
Fraying at the edges looks like a fouree. Its silver plated copper, not a nickel and copper mixture, which is what clad is.
If you want the coin you shouldn't be paying anywhere near the price of a "real" one. Made in antiquity for the purposes of fraud, they can be collectable in their own right. I have a few. Any dealer worth their salt would have it in the description.
I would say it is just based on the photo, however the weight is correct for a tetradrachm. The reference number they are using is for a didrachm though
I agree that the ancient counterfeiter did a good job to make this coin with pretty much the same weight as the real deal, I wonder if he managed to do this intentionally or if it is just coincidence.
For those new to the subject, I have several pages on plated coins illustrated with images that should help distinguish them from solid coins. http://www.forumancientcoins.com/dougsmith/fourree.html I need to work on more images that illustrate the topic more effectively. The one below does show core exposed by a broken edge to some effect.
