Question about clickbank

There is a product listed on clickbank for sell at 20$/product and I will get the 5%/sell if I promote this product...
Anyway the price on the site product is 50€... so I will get the 5%/sell of 20$ (as listed on clickbank) or of 50€ (the effective price listed on the site)?

The price listed on clickbank isn't the price of the product, it's the average commission per sale you will be making (including upsales i think, but not sure), so you should be making around $20 per sale.
5% is unusually low for Clickbank though, most commissions are between 50% and 75%.