SQL use 2D array with "CASE WHEN" _ "IN" _ "THEN" _ "ELSE" _

I am using postgres and GOLANG

Basically, I want to pass in a 2D array (doesn't have to be a 2D array, could be a struct or a JSON object). In the case where the first value matches a category of a product then add the second value else add 0

So, if it wasn't a 2D array and I want 100 for yes and 0 for no

...

+ (CASE WHEN products.category IN $1 THEN 100 ELSE 0 END)
...

$1 is just a simple slice of categories

But I was thinking about having an array like
[[1, 100], [3,50], [4, 120]]. So if the product category is 1 then I can add 100, if 3 then add 50 and so forth... else we just add 0

So the psuedo code would look something like...

+ (CASE WHEN products.category IN ($1).x THEN ($1).y ELSE 0 END)

The idea is that I can upgrade a sorting value of products with API calls.

I have played with unnest and tried some loop stuff but can't quite wrap my head around it, any SQL or GOLANG suggestions. I really want to keep they heavy lifting in the SQL queries

I actually figured it out, but i am not using CASE WHEN IN, I am just making a table of a json_object and doing left join and COALESCE

select products.uuid, products.category, COALESCE(CAST(catquery.value as integer),0) as value from products
LEFT JOIN (
   select key as category, value as value
   from json_each_text(
      json_object('{{1,20}}')
)) as catquery ON products.category = CAST(catquery.category as integer)

So with my api I just send over the json object as a string in the format '{{1,20},{3,100}}' and then pass this string in my query, below is a simplified version of my query:

select products.uuid, products.category, COALESCE(CAST(catquery.value as integer),0) as value from products
LEFT JOIN (
   select key as category, value as value
   from json_each_text(
      json_object($1)
)) as catquery ON products.category = CAST(catquery.category as integer)