Mostly correct, a new red key is circa. £800 as it needs all new keys, locks and ECU. Timpsons can copy a blue (or red for that matter) key, but it's not a genuine new blue key it's a copy of the other one.
As for needing it, only if you get problems with the ECU/immobiliser not happened (that I know of) on the Bravo/a range, but has been heard of on the Punto Mk1's as they're a bit older.