Invoice for a 4-dr manual tech is a little under $28,000. Edmunds true value says $28,200. I think that's a fair assumption for what they're going for now. It's $3400 over the price of the base TDI, not $4500.
The tech package includes:
HID with AFS package and LED DRL
Dynaudio
Kessy
RNS-315
Sunroof
I would not have bought my car without the HIDs (I waited months for one with HIDs to become available) and also think the Dynaudio was well worth what I paid for them at the time. I drive enough unlit, deer-infested country roads at night for the HIDs to make a difference. The AFS is also just cool. I test drove a base car before buying mine, and while I can't quite remember the actual difference now between the stock and the Dynaudio, I remember when I first got my car that there WAS a difference. I listen to music during my commute - having a nicer audio system was a good upgrade for my needs.
I also like my sunroof - I rarely open it, but I leave the shade open almost all the time - the added light in the cabin is nice, alleviates the cave feeling with the black cloth interior. I wouldn't mind the Kessy. The NAV is the only thing I wouldn't care for - adds to the cost and is more expensive to maintain than my $100 Garmin with lifetime maps updates and traffic. But, it's included in the package. For what you get for $3400, I think it's a good package.
Back on topic: OP asked about whether the 4 door option ($700 more than a 2 door) is worth getting the Tech package, since he can't find a 2 door with it. All I can say is that having 4 doors has worked out well for me, even though I rarely have passengers. It's just more convenient:
You can open the rear windows for ventilation.
Accessibility - when you do carry passengers, they will appreciate not having to climb over the seatback to get in the back.
Shorter doors
Less of a blind spot
Maybe the coupe looks better (I actually don't think so, I don't like how the rear window swoops upward on the 2 doors). But, it's all personal preference. To me, all I can think is, it's a Golf. Even a GTI looks like a rollerskate (boot on 4 wheels). But, of course, different strokes, since you're looking for something sporty. My car's my daily driver - it HAD to have 4 doors.