Been following these things about 2 years ago, and stopped 1 year ago after I bought something which I think would last me for 5 years. And I don't want to be tempted into spending more....
From that time, the "value for money" brands/DACs would be the uDAC (which I think was updated since) or the iBasso line, I think the D4 or something....
I got a uDAC myself and I think it's great
Those are in your price range I suppose. Of course you need to remember some DACs don't come with amps and you have to purchase time separately. So I would advise you to research well
Of course if you want to go into detail...head over to head-fi. Probably you would need synergy between DAC and amp, and the DAC and your Shures, and even synergy between the DAC/amp/headphone combo with the song genres which you hear and so on....
My 2 cents would be uDAC or iBasso but I've been out of touch for about a year now so take it with a grain of salt...