If your looking at buying a premium CAM addin for Solidworks look around a bit more.
I have used Camworks at my last company and it was pretty poor. Not straight forward to use, always having to sketch contain and avoid areas - though its been a couple of years.
I've been looking for quite some time and now are about to spend 40k on SolidCam, which is the best option for me as it is also well supported in Australia.
Support is what you want with your CAM, for training tips & post-processing mods.
Camworks in AUS was/is poorly supported.
I've just checked the quotes for SolidCam - yearly maintanance is around 12%.
Maintanance is very worthwhile as technology & machining strategies are improving all the time (should be improving...).
If you plan to be in buisiness for some time then I suggest keep up with yearly maintanance.