This article from BikeBiz.com outlines some of the problems and causes of the carbon fibre shortage. The following paragraphs are what stood out to me though:

The first consequences of the forthcoming price hike can already be seen, claimed Dr Weng. He said his R&D team have come across Asian bicycle components made from cheaper glass fibre, ‘wrapped’ in carbon fibre. Last year’s trend was for carbon fibre sheathing over aluminium cores, a shady practice but one that’s easily proved to be taking place (so long as you can bear cutting into your ‘carbon’ handlebars, that is). However, glass fibre cores can be dyed to look indistinguishable from the carbon fibre outers and it needs specialist testing to spot the duds.

Dr Weng said consumers should be made aware that carbon fibre bikes will not be coming down in price any time soon and that cheap-as-chips carbon parts and frames may not be all they seem.

Careful when ebaying for those cheap carbon components…