I bought mine as a growing herb in my local supermarket and have seen it at the local garden centre too so maybe try another supermarket. I keep mine year round on a kitchen windowsill.
I'm in Belgium so won't offer to post bits as they'll wither but you can also get the aniseed flavour from crushed fennel seeds (toast in a dry pan first to bring out the flavour) or, with fish and chicken dishes, you can use a spoonful of pastis such as Pernod or Ricard. Star Anise is another aniseed spice used in Chinese/oriental cuisine.
