Wired or Wireless DAC?

B60R / B&W DM630i
I'm auditioning an Audioengine D2 for the weekend. For $600, it is a Plug & Play device that does what it says. I have no complaints about setup or ease of use.
My question is, as my amp is about 30' (wired, 15' LOS) from computer, wouldn't I get better bang for the buck with a long USB and a higher end DAC (used)?
Please give any/all suggestions for DACs/USB cables/etc as I had stalled out for over 10 years and had no idea digital had come this far!
I'm not sure about the impact of this on your proposed setup but it sounds as if you'd be at the maximum recommended length for a USB cable.

This is from Wikipedia:

"The USB 1.1 Standard specifies that a standard cable can have a maximum length of 3 meters with devices operating at Low Speed (1.5 Mbit/s), and a maximum length of 5 meters with devices operating at Full Speed (12 Mbit/s).[citation needed]

USB 2.0 provides for a maximum cable length of 5 meters for devices running at Hi Speed (480 Mbit/s). The primary reason for this limit is the maximum allowed round-trip delay of about 1.5 μs. If USB host commands are unanswered by the USB device within the allowed time, the host considers the command lost. When adding USB device response time, delays from the maximum number of hubs added to the delays from connecting cables, the maximum acceptable delay per cable amounts to 26 ns.[40] The USB 2.0 specification requires cable delay to be less than 5.2 ns per meter (192,000 km/s, which is close to the maximum achievable transmission speed for standard copper wire).

The USB 3.0 standard does not directly specify a maximum cable length, requiring only that all cables meet an electrical specification: for copper cabling with AWG 26 wires the maximum practical length is 3 meters (9.8 ft).[41]"
Yes, thank you for the data. As it is close to (over) the limit and I am looking for Best Bang for the Buck, I was wondering if I am bending over nickles to pick up a penny?

Someone may have run a long USB and is able to report results, is my hope.
I don't have any experience with a USB run that long but it would be easy enough for you to try it and see how it works for you.

Monoprice sells really well-made cables at very good prices. The longest standard USB cable they sell is 15 feet. To go longer than that you'd need an extension cable or an active cable. For a total of about $10 plus shipping it would be worth a shot.

A factor in your setup decision may be that an 'audiophile' grade USB cable at that length is going to be pricey. Cardas and Audioquest, for instance, make 15' cables in the $300 range. Of course, you may not be an adherent of cable voodoo.

As I said, though, I don't have any experience with USB at that length and can't advise how it will sound but if that's the simplest solution I'd experiment with the inexpensive cables.
I ended up purchasing the D2. It was Plug & Play and I have been able to move on (J River, WAV v FLA v AIFF, etc)