CAE is Caprine Arthrititis and Encephalitis.. In adults, it mostly causes lameness through sore, swollen joints. In kids, it causes encephalitis with rear-limb paralysis and kills the kid. Many goats can be CAE+ and pass CAE to their kids with no symptoms whatsoever, though.
CL is Caseous Lymphadenitis, aka "cheesy gland." It's an infection of the lymphatic system by a bacteria called Corynebacterium Pseudotuberculosis. Generally causes big abcesses at lymphatic sites like the area behind the jaw and below the ear, or at the base of the throat where it goes into the chest, etc.. Wherever there's a lymph node, basically. It can also cause internal abcesses on various organs.
The cost of testing generally depends on your vet.. Both are blood tests, so it's basically the cost of drawing blood plus a handling fee and lab fee...possibly the flat-rate cost of an office visit. Just all depends on what your vet charges for that kind of stuff.
If you have the skills to draw blood at home, there are several labs out there which can run the tests.. Someone will chime in with lab names, I'm sure.