Two possible transfer targets with no transfer fee because they are free agents. Both have full seasons with a good scoring record.
The first one is 25 year old Óscar Eduardo Estupiñán Vallesilla ia Colombian professional footballer who plays as a striker for Portuguese club Vitória de Guimarães. According to Wikipedia. He finished the season with 28 appearances and 15 goals and 2 assists.
Second free agent forward is Bas Dost being released by Club Brugge in Belgium.
Dos has 14 goals in 35 appearances in the Belgian League. Both seam like good option for the Greens.
According to wiki “Bas Dost is a Dutch professional footballer who plays as a striker for Belgian Pro League team Club Brugge. Having begun his career at FC Emmen in the Eerste Divisie, Dost later played in the Eredivisie for Heracles Almelo and SC Heerenveen.” Wikipedia