help with ticket cost calculation

[Astro]

Beware: buses from Orio Airport to Milan do not stop in Bergamo, so if you want to visit it you cannot have MilanoCard discounts on buses (line Z301) or trains to Bergamo. However, they are covered by IVOL passes.

[Lucio Chiappetti]

Oh well, I keep forgetting about Bergamo airport ... you know, a company flying into Linate used to make a pun about that: "Milano sul serio, non Orio al Serio" (Milan for serious, not Orio al Serio, which takes its name from river Serio). It's the one with worse public transport connections to Milan.

Not sure if the buses from Orio still make an en-route stop at Cascina Gobba (border station of M2, you could take M2 there but still you'll go through Centrale M2, so you are likely won't save much time w.r.t. coach to Centrale and M2 to Cadorna). Otherwise you might consider from Centrale M3 to Repubblica (1 stop) and take S1 to Novate. Remember S3 from/to Cadorna and S1 from/to passante (this can be useful when you come into town from Novate).

As a resident I do not know this MilanoCard though I heard of it (I saw from its website it covers only the urban area too) and what additional advantages it has (entrance to museums I guess).
You still have to pay extra Novate-Milan, which I guess applies to most cases but the (Expo or not) "area piccola" or "area grande" cards. Verify advantages vs cost with the Expo card.

I guess that both the MilanoCard and Expo card won't change price in September. I expect no fare increase for the urban area, but usually there is a tiny increase (few cents) for rail and interurban fares at beginning of September

If you do not plan to spend a full day at Expo, the evening ticket is a reasonable arrangement, but how to get there and back to Novate in a reasonable way ? If you are around in town in an arbitrary place, probably best is M1 to Rho Fiera M1 (but that is not within the urban area !). From Novate take S1 to Lancetti (or S3 to Bovisa, then any S bound to Lancetti, 1 stop), than retrocess from Lancetti to Rho Fiera "rail" with S5/6/14 (not sure about S11), and viceversa to go back. As the crow flies Novate is not too far from the rarely used Expo entrance of Roserio, but I do not know about bus connections from Novate, nor about the pleasantness of the area in the evening. A taxi could be reasonable as travel time, but I'm not sure how easy is to call one in Novate, and not speaking italian.

Essentially from Novate S3 leads you to Cadorna, which is within absolute walking distance from the Castle and its museum, from S.Maria della Grazie (and the Last Supper, but you need to book for that), from S.Ambrogio, the Science museum, and from corso Magenta and the Archeological Museum (not a first choice for a tourist with few time) and S.Maurizio (which instead I consider a must, recently restored, and free). A longer but fully feasible walk is required to go either to Duomo, i.e. the real geometric centre, or to the Brera Art Gallery (best way through Castle).
If the first train is an S1, do not wait for S3. Take the S1 and alight at Bovisa. It is likely that you will find an S train from the other branch or a regional train taking you to Cadorna, or you can stay on S1 and go to Lancetti-Garibaldi-Repubblica-Venezia and beyond (the same occurs if you take the wrong S).

At Lancetti there is nothing to see (unless you want to change to S5/6 for Expo). At Garibaldi there is the new skyscraper area of Porta Nuova and restaurants in Corso Como, there is also an Eataly in piazza XXV Aprile at the end of it, and then access to the centre via corso Garibaldi or Solferino-Brera. At Repubblica you can change to M3 (to Duomo, southbound, stop at Montenapoleone for luxury shopping, and to Centrale northbound). At Venezia you can change to M1 (again to Duomo southbound) or access the popular shopping area of corso Buenos Aires (northbound), or walk to the centre ... the first part has no shops but pleasant buildings, then you come at the other end of the luxury and fashion area, then from S.Babila can walk to Duomo through a pedestrian popular shopping area.

Not sure whether you are more in arts, shopping or food. In arts and history I would recommend also the Gallerie d'Italia in piazza della Scala, and the churches of S.Lorenzo and S.Eustorgio towards south (reachable by tram or walking through the other popular shopping area of via Torino; if you are in arts enter also the church of San Satiro but only after you have looked at its back and seen how flat it is, then enter and surprise). Then you will be near Porta Ticinese, where the newly restored Darsena (harbour) is pleasant and leads to the Navigli (canal) area with various restaurants and alike. The same is reached mid-way from Porta Genova M2.

I think I incidentally listed also the main shopping and food areas in the above. Could add details about arts and history. The only place really of some interest outside the centre (I hope nobody from Garegnano or Fontana will complain) is the abbey of Chiaravalle (M3 Corvetto than bus 77), but I would place it second choice if you have few time.

Concerning Bergamo, I am not sure how easy is to arrange a visit en route from/to airport. The only advantage is that you'll possibly find a left luggage facility at the airport (forget about finding one in a rail station ). But then you'll have to take a local bus to Bergamo rail station, than possibly a local bus crossing the Lower Town (Berghem de Sota) to the foot of the funicular, and go up to see the Upper Town (Berghem de Sura), which is the nice part. Then you'll have to go back to pick up your luggage. Of course you can travel by train from Milan to Bergamo ... but where can you store your luggage ?