TIDAL on SALE!

This appears to be their ‘HiFi’ tier and not their highest, ‘Master’ tier.

Tidal's standard tier is called "Premium". The tier that supports hi-res MQA is called "HiFi". That's what I saw on their website. 

Regular price for premium is $9.99/mo. Regular price for HiFi" is $19.99.

Someone who has the high tier Tidal subscription, please correct me if I am wrong.

They appear to be hurting for business. Over the holidays they ran $5 promo for five months. I dumped them a year ago....Qobuz is currently the best streaming service in US for a bargain price of $149.99 / 12 months. 

If you go to Tidal.com and scroll down a little it lists Master, HiFi and Standard as the levels of quality in decreasing order.

Here, straight from Tidal, the info:

https://support.tidal.com/hc/en-us/articles/115003662825-Subscription-Types

There are only two tiers, Premium & HiFi.