I Need an XLR Digital Cable.

Q1. Has any one started with a $20-30 one then later tried $100 cables and see a (big) jump in performance? I’d like to hear from those whom actually did the A/B tests. 

Q2. Should I start with the under dog, no name brands, hyped or should I start with big name brands’ entry levels? 

I’m using 1 analog XLR cable as a digital cable from MIT MI-330 to play/ verify the benificial of having a DAC .... and it sure is. 
(Ayre cx-7 CD player only provides 1 XLR as digital output source. )
Yes you definitely should hear a difference in AES/EBU cables. In my (admittedly expensive) system the difference from moving from generic to AQ Eagle Eye, then Wild, then Marigo and Transparent Ref XL was very clear. Different cables will bring different attributes, for example in my system the Marigo is more clear and detailed, more "studio sound" while the Ref XL has warmth and naturalness, the latter suits CDs so I use it for those while I have Marigo when playing SACD.

A good recent discussion of this topic and recommendations at your price point is here (while the thread is about RCA/75ohm the same manufacturers make great 110ohm cables as well)
IMHO, I would buy an entry-level first, something made from Mogami or Canare 110 ohm cable. This will get you going with a decent proper connection for cheap. That also gives you a reference should you try something with a return privilege.
Thank you @tls49
I just won eBay some entry level ones (junks?) to test out then will move on up from there.
. Sommer Cable Binary 234 from Germany, $32. (Not so popular here in US so hoping it’s a bang-for-buck.
. Canare DA206, 110ohm, $25.
. Mogami w3080,110 ohm, blue, $20
If I find these entry level digital cables perform worse than my loaner analog XLR MIT Mi-330, I don’t know what to say...

Next on radar:
. Wireworld Starlight 7, $100