On an ECN or raw-spread account, the broker shows you near-interbank spreads but charges a separate commission for routing the trade. Typical commissions are $3 to $7 per standard lot per side, or $6 to $14 round-trip — about 0.3 to 0.7 pips of equivalent cost on a major pair.
Commission-based accounts are usually the cheapest option for traders placing more than a few trades per day. Standard accounts with wider spreads but no commission can be cheaper for very low-frequency traders or holders of short-term positions on less-liquid pairs.