Its tough to tell from the pictures, especially since the faceplate is scratched up and theres no cable, but based on the way the bass knob markings look I believe they may be fakes. The markings on my genuine ones purchased from amazon seem to look a bit different, much thinner lines and all are of the same length. In this case it would be tough to test for the usual giveaways since there's no cable, obviously, but two of the main ones would be the bass knob having little to no effect and a red chip possibly missing from the cable. The other is even more obvious... they'll sound like total crap. Gonna have to agree with the people on the other thread though, if in doubt about their authenticity please do not sell them, since if they do turn out being fakes it could lead to a number of problems down the road, none of which will likely have a happy resolution. Unfortunately there seems to be more fake IE8s/IE80s than real ones in circulation, so extra care is usually required to even sell them, such as providing a receipt from an authorized retailer etc.
However, the purpose of my post wasn't to rant about business ethics, I just wanted to point out that there's a very high likelihood that these are fakes. You should take a look at this thread about how to further identify fake IE8s/IE80s, though its quite an old thread and some of the information might be out of date, as the counterfeiters are getting better at it all the time. Honestly, I'd suggest just keeping them and buying the cheapest ie8 cable you can find to try them out. Worst case scenario is you have fakes and you only wasted 20-30 bucks or so. Anyways, check out this thread for more info on how to spot fakes: