I'll give it a try; the first tme you get a check engine code your looking at about $70.00 us just to find out what it is.
When your intake manifold clogs up and it needs to be cleaned your looking at about $400.00 for the dealer to clean, so the egr mod in the long run will save you that. Even if you do it yourself your looking at about $20.00 in shop supplies and 4 hours of work (how much is your time worth an hour?)
If you plan on keeping your vehicle for awhile, you will need to do a timing belt change. Your looking at $400.00 on a good day for the dealer, and they seem to have a hard time getting the timing spot on, another reason for vag-com. If you do it yourself, you will need vag com. Can also use for many other functions/option but trouble codes and timing checks, egr mods, will more than pay for it.
As far as manual, I'm having a tough time with that. Yes you will need one. Be aware that there are two types of paper manuals, one is the "Factory Service Manual" and that is the one you want if you decide on paper. The other is just a repair manual and is geared up more for the weekend mechanic/Mr. fix it. I have read here that the repair manual is short on all the fault codes and such (has some not as many as the factory service manual). Missing a few other things that perhaps someone with both manuals can elaborate.
The cd supposedly is very complete but some have complained about the difficulty of use while making repairs and such. I suppose you can print stuff up ahead of time, but chances are you will still need to reference an item or two from a different section while working on you car. I am opting for the paper factory service manual, if anybody has a good source of in stock, let me know.
Your pricing varies depending upon which product you choose. The base price is $199 for program and cable, see the vag-com website for more info.
Is it worth it? Yes, could it be a better price? Yes (I'm a cheapskate). I think they would sell more if they had a lower price, but remember, the software is only $99, and the data cable brings you to $199. You can make your own cable but then no support by vag com, and once again, how much is your time worth TIME IS MONEY!.
Is it easy to use? I am new with it and am learning very slowly. When provided info on steps of how to do it (like the egr mod in the faq) it is very easy. To try and figure out how to do something from scratch, it is tough. You can ask on this site and most of the time you will get helpful responses, sometimes people are having a bad day and give you grief for not knowing. I guess they forgot what it was like to be starting out. I am slowly learning and should probably let someone else answer that question. Hope this helps, Kevinski