If you buy the game new you won’t have to pay anything extra. This payment scheme is for EA (other publishers are planning similar schemes) to make some money from used game sales. At the moment publishers, and therefore developers, make nothing from used game sales.
Some high street stores are rumoured to be promoting second hand copies ahead of original copies because of the greater margin.
The upshot is this. If you buy new you won’t be affected. If you buy used games at the current prices you may end up paying more than if you had bought new. I assume used game retailers will react by dropping the price of used games, but that will likely mean a drop in how much they pay out for trade ins.
Also worth noting that for the time being at least this only affects online content