Frank,
The answer to your question then becomes what are you prepared to put in in order to get the most out of your NX experience. Which is to say which modules you would buy and get a lot of use from. For example if you buy basic NX you don't get the full sheetmetal package. I think not having that would hold you back considerably.
Once you have the sheetmetal package there is also an advanced version which grants to access to a curve based flat patterning tool which doesn't require you to design your part using all of the sheetmetal features. Rather you can just use your experience to design a chunk solid, shell it out to a constant thickness and then flatten it. Some people would disagree and regard that approach as undisciplined, but it is very quick and easy and your question was basically about bang for you buck. I think you should talk to you sales guy about all the options and do the maths based on your best needs fit.
Best Regards
Hudson
www.jamb.com.au
Nil Desperandum illegitimi non carborundum