Is the price paid for acquiring REs included in the buy average calculation of the rights issue shares?

No, the price paid for acquiring Rights Entitlements (REs) is not included in the buy average calculation for the actual rights shares you subscribe to; your buy average for the new shares will only reflect the subscription price you pay for them. The cost of buying REs and the subscription price for rights shares are treated as separate costs when calculating your overall investment cost for that specific company.