Well, an AMD FX 8320E sells for less than 110€, while the Intel Core i7 3930 sells for over 500€.
Sounds like AMD has a very competitive offering, both in terms of price and price/performance ratio.
Unfortunately as merb already mentioned the performance to power ratio is not really good for AMD, which I guess contributes quite a bit to AMDs lost marketshare in the server segment (plus it doesn't look good in reviews which is bad for AMDs mindshare, which already is far behind Intel and Nvidia). And until Mantle/Vulkan/DX12 the performance in quite a few games was noticable behind Intel because AMDs single core performance was not on par which was bad because DX11 is basically single threaded. [1]
Overall I guess AMDs biggest problem is the mindshare. Wheras Intel or Nvidia can allow themselves one or two not so great generations, AMD tanks as soon as they have problems. AMDs HD 5000 generation was out sooner than Nvidia, faster and more energy efficient, but it only helped them gain 5% marketshare (around 45% at the time). AMDs 7000 generation could compete with Nvidia, but used more energy and bang, Nvidia regained more than the 5% percent that they lost, and that continued with Maxwell (they now have ~75% marketshare even though AMDs cards can compete on performance). [2] The same with Intel, when AMD could compete, and even beat Intel in performance and efficency over many years, they gained not that much marketshare (in part because of Intels shady manipulation, but in part probably also because of mindshare). Intels Conroe could regain some of the marketshare Intel lost thanks to its Pentium 4 (which reduced AMDS ~48% to 35%). Then came Bulldozer, which was underwhelming outside of multithreaded tasks and late in part thanks to GloFos 32nm problems and now AMD has aroun 20% marketshare). In the server space it's even worse for AMD with less than 1% marketshare compared to 25% around 2006-2007.
[1] http://www.littletinyfrogs.com/article/460524/DirectX_11_vs_...
[2] http://cdn.wccftech.com/wp-content/uploads/2015/04/Nvidia-AM...