^ is not the kind of advice I would be taking... this is setting you up for career suicide with your current employer.
My suggestion to you regarding the new opportuntuy, is to determin whether this new position will have you learning a skill that is going to be marketable.
You must also determin what if any lifestyle changes the new position will require you to do... ie, travel, longer hours etc...
Also, I would do some soul searching as to why you should consider making a move. Is there anything that your current employer is not providing you or that you would ideally like from them.
Making a career move for more money is not making a career move, it's making a financial move... there is nothing wrong with that, but if money is your sole motivator, well, you could probably make more anual income by going contracting, then moving to another full time permanent position. The difference after taxes is negligible.
It is quite likley that I have some "inside" knowledge regarding the company you are considering... I'd be happy to pass along any info I have to you... just shot me a pm...
HH