Spreads and costs
Three things decide what a trade costs: the spread you cross to get in, any commission on the way in and out, and the financing you pay for every night you hold it.
The spread
The spread is the gap between the bid and the ask. You buy at the ask and sell at the bid, so a position starts marginally down by the width of the spread and has to cover it before it is level. On a short hold, this is usually the largest cost you pay.
Spreads are variable, not fixed. They are tightest when a market is deep — the London and New York overlap, for a major pair — and they widen around economic releases, at the daily rollover, and in the first minutes after a weekend open. Any "from" figure quoted anywhere in this industry is the tightest available, not the one to plan around.
Commission
Where an account charges commission, it is a fixed amount per standard lot, normally charged on both sides — once when you open and once when you close. Because it does not move with the market, it is the only part of your cost you can calculate exactly in advance.
Overnight financing
Holding a leveraged position past the daily rollover means paying or receiving a swap, set by the interest-rate difference between the two sides of the trade. It can be a credit rather than a charge, depending on which way you are positioned. One day each week it is normally applied three times over, to cover the weekend the market is shut.
Swaps are irrelevant to a day trader and decisive for anyone holding for weeks. Over a long enough hold, financing can quietly outweigh the spread that got you in.
Where the figures are
Live spreads and the exact swap on any instrument are in MetaTrader 5 — right-click a symbol in Market Watch and open Specification. Those figures are the ones your orders execute against, they update with the market, and they are more current than any table on any website could be. Commission applicable to your account is set out in your client agreement.