Selling gear made to be a set

Take the highest bid either way.

Try to sell the set for a period of time, if no dice, split it!

I think most buyers on Audiogon are willing and able to easily research sales prices for gear. If I were you, I’d price the set to move using current sales data, etc. It’s not uncommon for me to see pricing from individuals higher than dealer pricing on preowned and open box. I’ll buy from the dealer generally if the pricing is close, especially when there is a return option, or warranty that will be extended. I think some sellers struggle to understand the options available to buyers. 
 

Sorry for the long winded answer, I enjoyed some dark beers this afternoon. 

If you list them as a set, you'll probably limit your potential pool of buyers; so, I'd list them separately. However, I'd put a note in each ad that you will offer a discount to anyone who buys both items.

Unless you are in need of cash, I would put the gear in storage just to make sure going purely streaming is your final solution.   I own every piece of gear (including the boxes and manuals) all the way back to my first system in 1977.  I have 5 different listening rooms with various states of Vintage Gear or themes, and the rest is in storage or rotates in the rooms.  I'm glad I've never parted with any gear.

My wife...not so happy.

In general, separate most items. Your two items should sell together. They were designed to complement each other.