Re: Best travel card for commuting in Vaud?
You'll need a 5-zone "abonnement" for Lausanne - St-Prex: SFr. 159.- (1590.-) / month (year).
Or a 6-zone abonnement for Lausanne - Etoy: Sfr. 183.- (1830.-) / month (year).
If you get the 6-zone abo (Lsn-Etoy), it will also be valid for Lsn-St-Prex, Lutry, Renens, Morges, Allaman, Prilly...
If you get the yearly abo, you'll get two months free (compared to monthly abo).
Bring a recent printed passport photo with you.