If statement between 2 tables - reproducing sql

Hello,

my sql statement is: 

-- This query calculates the applied discount rate for SKUs based on their retail prices and effective prices.
WITH OnDemandPrices AS (
    SELECT DISTINCT PartNumber, PayGPrice
    FROM vnomic_Daily.Fct_EA_AmortizedCosts
    WHERE PricingModel = 'OnDemand'
),
RetailPricing AS (
    SELECT
        a.PricingModel,
        a.BenefitName,
        a.ReservationName,
        a.PayGPrice,
        a.MeterCategory,
        CASE
            WHEN a.PricingModel = 'Reservation' THEN MAX(od.PayGPrice)
            ELSE MAX(a.PayGPrice)
        END as RetailPrice,
        MAX(a.EffectivePrice) as EffectivePrice,
        SUM(a.CostInBillingCurrency) AS SumCostInBillingCurrency
    FROM vnomic_Daily.Fct_EA_AmortizedCosts a
    LEFT JOIN OnDemandPrices od ON a.PartNumber = od.PartNumber
    WHERE a.Date >= '2025-04-01'
    AND a.Date < '2025-05-01'
    GROUP BY
        a.PricingModel,
        a.BenefitName,
        a.ReservationName,
        a.MeterCategory,
        a.PayGPrice,
)

So I have the issue with setting DetailPrice variable using DAX. 
What i would like to do after is to add this detailprice to matrix. 

So we have 2 tables here so somehow i need to join tables before applying dax. 

What can be your approach ? How you would resolve it? 

Best,
Jacek