The market price is not a single item.
It is composed of several streams of data.
market prices during normal trading
First we have the Time of Sale data, which represents each transaction that has already taken place in the market. This is the data that is used to build candle charts.
Then we have the limit order book data. This data has several parts. On the bid, we have the Buy orders that have prices lower than all the sell orders. On the Ask we have the Sell orders that have prices higher than all buy orders.
The level 1 is the composed of the Best Bid and Offer in the book.
In many markets like the NYSE and NASDAQ there are many order books that compete with each other. Each of them keeping a set of bids and offers available for execution. The best prices of the combined books is known as the National Best Bid and Offer or NBBO.
When you send a market order to buy. Your order is executed against the limit sell orders that are available to sell at the time of your order's arrival. It will execute first against orders at a lower price, and if your order is too large to filled at a single price it will continue taking out sell orders at subsequently higher prices.
your particular scenario
In your particular case, your broker may be showing you as the "real time price" the price of the last sale, the price of the bid (many forex brokers do this). If they are showing you the ask price, then you would notice that you are able to consistently sell at the real time price, if they use the TOS price then you will see the price flickering up and down 2 or 3 cents as the orders come in to buy or sell.