Catridge for sme 30/2

Thinking of Dynavector 17dx catridge , my local dealer says that’s a good match

This looks like ''back to front'' causality. From effect to the cause.
In some sense one can ask the right cart for the given tonearm but
the right cart for an TT is curious. As far as I know only our Lew
can have this this problem because of the number TT's he owns.
It seems obvious for him to ask the question ''which cart should
I use for this (x) one?'' 

Not sure why do you need such expensive cartridge if you think your tech knowledge "in setting up table is bad" ?

You can find excellent cartridges under $1500 and all you need to know is tonearm effective mass and cartridge dynamic compliance (at 10Hz) to theoretically match them together reading this article.

Maybe a cartridge with user replaceable stylus (MM or MI) is better for you ? 

Cartridge set up on the SME 30/2 is very easy if you follow the instructions in the manual and use the supplied protractor. Probably one of the easiest systems around. You simply bolt the cartridge into the holes, level the cartridge and then adjust the pivot to stylus by moving the back of the arm in the slide to bring it into line with the protractor - cant get any easier than this.

Dynavector 17DX should be a good match. As a former SME importer I experienced good matches with both Dynavector and Van Den Hul cartridges - their medium compliance matches well with the SME's low/medium effective mass. Also had good results with Soundsmith at the upper end of your budget.