How much $$ do bells and whistles add to preamp?

If a preamp with an outstanding volume control as well as the ability to adjust the amount of gain on each individual input is important, consider the Coda 07X. It’s volume control is the best in my limited experience.

Integrated might be a sound option (hehe)

Seriously, I stumbled across Odyssey Audio a couple years ago ... thank the Lord!

Give them a look!

Have a look at a canary c803 there is a nos one on eBay at the moment it is a four chassis design so true channel preamplifier. Each channel has its own power supply and each channel has its own volume control.  The volume control is a stepped resistor ladder. Is is at 7500 USD. This is at the very top end in my opinion. So that would be what I would like if I wanted tubes. 

Solid State my favorite is Ayre k1xe preamplifiers. Same thing it has  a stepped resistor ladder for a volume control. 

Now to your question minimalist design s are generally more money than ones with a bunch of extra junk on them. That being said there are some cheap minimalist design preamplifier s that only offer one feature which is low sound quality. 

Regards

If its a  $6k pre, an add in DAC probably adds around $1K to the retail price - that's very much a ballpark estimate. However, the critical point is that unless you need dac / streaming functionality, then you are better spending your money on a preamp that doesn't have those features.

It's worth taking account of your long term plans for your system. If you plan any digital upgrades, then you may end up with a separate DAC and a redundant DAC in your pre, and a less good pre than you would have had if you had forgone the inbuilt DAC in the first place.

Or….you could use the DAC - Streamer as a pre-amp…

Since the recent APEX Upgrades to the DCS line of DACS, there are a few Bartok’s out there for good prices on an amazing sounding DAC.

Or… get a used ARC Ref 6 - maybe one of the finest Pre-Amps out there and work your way up the DAC ladder over time.