Having just bought a new 3D TV over Christmas (In my case a Sony Bravia KDL-55W829B) I needed to get some more 3D glasses and the Sony ones are expensive at £50 for a twin pack.
Doing a bit of research it would appear that most of the newer TV's that use Active 3D technology also use the same glasses technology, just packaged up a little differently. On AVforums one of the members there ordered these same glasses from China and they cost £16.50 but he had to wait weeks. I've been searching around for somewhere in the UK and they are actually quite difficult to get unless you want to pay silly prices.
However Richer Sounds are offering these twin packs in store only for £21.50 which all things considered is quite reasonable... and in my case I'll be collecting two twin packs tonight, going to be watching Guardians of the Galaxy in 3D tonight!!
I know 3D is on it's way out, most people are not interested by it but I still like it and my TV does a very decent job of displaying it :)
NOTE: these are ACTIVE glasses, and I take no responsibility if they don't work with your specific TV so please check first.
For 3D thrills from your 2013 Samsung 3D TV, take a look at the fantastic value Samsung SSGP51002 TWIN PACK 3D glasses.
Light and comfortable to wear, the Samsung SSGP51002/XC 3D glasses are an improvement over previous active 3D glasses. The high arms ensure a comfortable fit with good periphery vision retained. These active glasses also benefit from a long battery life.
Compatible with all 2013 Samsung TVs with active 3D TV technology.