A holiday decoration facility processes coloured glass into ornaments in a joint process. At its split-off point, ornaments can be further processed into ornament- garland decorations. Which of the following is irrelevant in deciding whether to sell ornaments at their split-off point or to process it further to make ornament-garland decorations? Sales value of ornaments Sales value of ornament-garland decorations Joint costs incurred to process the coloured glass into ornaments Cost of further processing the ornaments into ornament-garland decorations