All "Costs" are really just estimates.  The real key here is... is there actually a performance problem?  How long does the query typical take to execute, how many CPU milliseconds...

Based on the fact that someone used the YEAR() function in one of the renditions of the code, can we safely assume that the t.tabdate column is a DATETIME column? ...

If it were an NCHAR, you would need to be seriously concerned no matter what.  I ran into this problem before with some system tables (can't remember which ones just...

Here's the link for the current definition of PARSENAME.
https://docs.microsoft.com/en-us/sql/t-sql/functions/parsename-transact-sql

But Books Online and the link above is incorrect.  PARSENAME actually returns an NVARCHAR(128), which is the...

Both the Democrats and the Republicans found out both how wrong a survey can be and how it can actually sway what's going to happen if it's published in real...

This will give you the same output as that which you posted...

DECLARE @OtherLimit INT = 6
;
   WITH ctePreAgg AS
(
 SELECT  product_name =...

Yes... might as well get it from the master herself.  Do the following search.  Any of the videos with "(MCM)" as a part of the link title are totally awesome.