XLR cables, worth buying higher end?

I have been completely satisfied with balanced interconnects made with Mogami W2549 cable and Neutrik XLR connectors. These can be made up for you by many pro audio shops. Last time I looked, a pair would be considerably less than $100. You might even get both pair for that.

I had mine made up by ProAudioLA.
I compared them to some expensive name-brand cables with glowing reviews. To do that, I ran single-blind comparisons with four friends, each separately. We all found the expensive cables to be noticeably more colored.

On my big Mac amp the extra gain made the amp idle is more prominent. I had to put a pad on the line to get rid of the hiss.

NO!

I get excellent sound quality using Canare Quad Star XLRs from MarkerTec.

They are inexpensive Pro cables used with Pass Labs equipment.

Work better than RCA cables for short (3ft) and long (15ft) runs in most cases.

Mogami W2534 Neglex Quad Pro only $1.59/ft.
Neutrik NC3FX-B and NC3MX-B $18.07 each.
Basic soldering skill in 1 evening and tons of fun, you get yourself a pair of decent XLR Balanced connector.  

Any diff between microphone and interconnect xlr cables?

seems mogami xlr used for interconnect seems a solid choice.  Not hearing much to be gained spending $500 or more for a 3ft xlr pair.

and saying this after spending $3k for speaker cables