A 500 ₺ listing with 20% commission
Revenue excluding 20% VAT is 416.67. Commission is 100 on the gross price. With 200 cost, 40 shipping and 10 packaging, the total cost is 350 and the net profit is 66.67 — a 16% margin.
Price 500 · cost 200 · commission 20% · shipping 40 · packaging 10 · VAT 20%
Net profit 66.67 · margin 16%