Well I had a look and here is my total :
Advance tickets that you need to book right now :
- (446€ Genève 07:39 - Monterosso 17:05 (2h30 for lunch and transfer in Milan) → way too expensive trenitalia.com)
To save a lot of money, take this route :
- IR90 Genève - Brig 07:10 - 09:32
- IR Brig - Domodossola 09:40 - 10:08
3 x 24 CHF + 1 x 12 CHF = 84 CHF sbb.ch
- EC Domodossola - Milano Porta Garibaldi 10:17 - 11:38
- transfer 2h30
- IC Milano Centrale - Monterosso 14:05 - 17:05
137.30€ trenitalia.com
Literally half the cost if you leave Geneva half an hour before. The connections are guaranteed.
- 115-180€ Monterosso - Roma Termini trenitalia.com
- 138-193€ Roma Termini - Venezia S. Lucia trenitalia.com
- 135-180€ Berlin Hbf - Praha hl.n. bahn.com
- 83-168€ Praha hl.n. - Wien Hbf tickets.oebb.at
Total : 700€ (750$) for the cheapest connections but 950€ (1016$) for the more expensive ones. Passes would be 889$ + 148$ (1037$) and you have flexibility. Now you can choose...