MULTI-BUY 3 for $20.  1 litre sized pot.  Campanula pyramidalis is a beautiful campanula that has a basal cluster of leaves from which emerge pyramidal spikes of purple/blue flowers in summer.  It acts like a biennial so is best left to set seed.  Tolerates full sun/part shade, reaching 1m +.  Selecting this gives you 3 x 1 litre Campanula pyramidalis plants for $20.