To DAC or not to DAC?

Thanks for all the quick and informative feedback. My local audio dealer is an elitist and generally condescending - not the best qualities for a retail environment, but I accept his personality and use his establishment as a well stocked, window shopping destination. So the prospect of a loaner or purchase at MSRP plus tax, aren’t very encouraging. Usually, after I experience the gear I’m interested in, I go online and hunt down the lowest price with no tax and hopefully no shipping. 

I chose to direct my digital outputs (MB100, OPPO 205) to the DAC in the MX122 because it was the newest/latest and I have good faith in Mcintosh gear. So, to refine my question - is a $3000 dedicated DAC going to make an obvious improvement over the internal Mcintosh DAC? 

@gwbeers 
 
The ~$1800 Benchmark DAC3B is basically totally transparent; so no, a $3000 DAC is wasting money. And again, there are DACs almost as good as the DAC3B that’s much cheaper.

One wonders, is the "condescension" earned or a reward???

My local audio dealer is an elitist and generally condescending - not the best qualities for a retail environment, but I accept his personality and use his establishment as a well stocked, window shopping destination. So the prospect of a loaner or purchase at MSRP plus tax, aren’t very encouraging.

Usually, after I experience the gear I’m interested in, I go online and hunt down the lowest price with no tax and hopefully no shipping. 

Using any bricks and mortar store to demo and then buy elsewhere cuzz it's cheaper is just plain wrong.....IMO

Instead of ’cuttin’ the op for his private comment in the thread about his purchasing habits, which IMO are his own business, not mine! For those who think they are the "Audio Morals Police Force." I suggest you take it offline.)                         
I will go back to the other question raised in the responses..Which is: is there a difference in DACs, and why such a big price spread? I have to say all audio components have a ’big price spread’. So do cars, homes, vacations, watches.. You name it the item can cost litle or a lot. DAC are no different.
As for sound... I have a DAC I paid $250 for, used. had it around fifteen yeasr? anyway, I finally found something I thought was enough better to buy. $250 vs $7,000 to gain a small improvement in sound. It was no earthshaking oh my gawd change. Just sounded better ENOUGH.