I more or less agree with destruct.. it is possible to make a good living in this field. If you have alot of skills and talent you'll go far. You can also be hamstrung by your own personality, where you are located and your goals versus your training and reel.
A computer science degree can be applied towards the field and might even be a good degree to fall back on if all else fails. However that degree alone will not get you the work you want and you may have to go out of your to create projects during your CS studies that you can make a reel from.
There will eb alot of competition to get the 100k job and it wil take years of experience to obtain that kind of pay. There are however positions out there that offer that but not to anyone who just graduated or just got into the industry... doesn't work that way.
It also helps to know people and to network. Reccomendations are highly valued and the more people you know the better and you get meet alot of people in a few years that can help you out. This is one good reaosn to go to a school that specialises in CG because you will run into the same peopl you went to school with later on int eh work place and many schools do have connections to production studios.
That being said there are alot of bottom feeders in the industry and by this I mena companies that hire inexperienced newcomers, pay them little and expect alot. It's likely that at some point you'll encounter this type of company. That is not to say that this is allways a bad thing. Sometimes you may do great things with the right people no matter what the pay is. If you are treated with respect then it's fine and you get the chance to build up that all important reel.
Most of the big places offer pretty good pay and benefits.. they also expect alot of dedication but most of the film places have downtime. The gaming industry has gotten a bad rap as of late because of companies like EA but not everyone has the same experience.
To answer your question.. how high? If you own the company you can be a millionaire but really you should be asking what is reasonable. In the states I'd have to say that entry level is roughly 25-35k, experienced is 35k-75k and senior and supervisor positions can be 75 to over 100k. Some specialized positions like flame operators or colorists can also make upwards of 100-200k but these are people who have alot of experience and have worked on projects everyone has heard of or seen and could be qualified as rockstars.
Since you seem interested in film you will need to specialize. Being well versed in natural phenomenon, hair, voxels etc are still niche skills as opposed to modellors which there are too many of.
Hope that helps