The digital-project price is only part of the build budget. Before purchase, total filament, adhesive, motor, ESC, servos, battery, receiver and radio equipment. For a large model, also consider print time and assembly space.
Free test parts help verify the printer and thin-wall process before a full aircraft is purchased. A successful ordinary print is not a substitute: these models use specialised walls and prepared profiles that require accurate extrusion and good layer bonding.
Projects suit FDM-printer owners prepared to configure a slicer, inspect the first layer and assemble RC electronics. A beginner should start with a free model and read its guide first. A digital package is not a finished aircraft.