Planning to sell my Micro DDX-1000, recommendations?

Do your homework and check hifishark for current prices. You'll notice it's all over the map, but at least you can extract an average price that will likely sell (the ones with top prices generally don't sell).

The best approach would be to split up the package. Both the Dyna and SME arms are quite collectable and you'll have a better change selling them separately. Selling cartridges is the hardest part, but neither are worth much anyway.

Of course it's none of my business, but why sell? If your aim is to improve the sound, you might consider buying a better cartridge. Both arms are capable of handling much higher quality cartridges and the table is decent enough not to obscure such an upgrade.

Better to sell turntable locally as to ship fragile stuff is always a risk. Also people like to pick up turntable from hands directly.
Dynavector DV-507 is high end tonearm and it doesn’t fit price level of turntable so better to sell it separately.

Try US Audio Mart or UK Audio Mart if you want to sell your stuff. 
This is the best market place with NO sales tax for the sellers, FREE listing! I always use UK Audio Mart when I have to sell some for lowest possible prices, because they charge nothing. Amazing place for used Hi-Fi gear.

Ebay and PayPal charge nearly 15% of the total cost and this is the worst place for the sellers in my opinion. 

In my opinion, either one of your two tonearms is worth as much as or more than your DDX1000.