Quick Question about my upcoming trip.

I am flying from PIT-SFO-TPE on Aug 1st. I know Aug 1st is the first day that the new Polaris is being offered between SFO-TPE with the retirement of the 747. Currently an upgrade to business is 860$. I couldn't care less about the PIT-SFO, maybe I can hope to get a complimentary upgrade, but my question is, Is there anyway to pay to upgrade only one flight or is only for everything? Also, if I choose to pay to upgrade, should I do it now or wait for it in hopes it becomes cheaper.

Welcome to FT!, kdfu685

Yes -- the online offers will generally be per segment.
In some cases, an upfaring approach, the price may be the same for PIT-SFO-TPE and SFO-TPE

Impossible to know in advance -- it can go either way and in the end there may be none or it make be cheaper.

What do you mean by this? If from "Manage Reservations" you should take it! You will not see a better price.

Actually, in many cases it will be substantially cheaper to upgrade the entire route than to upgrade an individual segment. The exception, as WineCountryUA notes, are the online offers that may appear during the purchase process and again during check-in.

Unless you have an exceptionally expensive economy class ticket (for example, a fully refundable or unrestricted ticket), $860 seems like a pretty low buy-up offer. A miles + cash upgrade from deep discount coach would cost $600 plus 30K miles (in one direction). Although it's always possible, personally, I wouldn't bank on finding a much better price.

So by upgrading the entire route, what fare class would I be/expect to be in? Currently I am in V.

It depends upon how you go about your upgrade. There are two ways to get into the premium cabin. The first is to upgrade an individual segment without re-faring the ticket. That's what you see when you get the option to upgrade one leg at at time during purchase or check-in. You can end up in almost any fare class when you do that (there's a thread about this on the board -- look for 'some upgrades earn PQDs and some don't).

The other approach -- which is what I was talking about wherein it is often (usually) cheaper to upgrade an entire direction of travel -- is to re-fare your ticket as a business class ticket. In that case, you'd (re-)book into a discounted business class fare -- typically P.

However, I don't see any P fares filed from PIT to TPE, and the SFO to TPE P fare doesn't appear to be under any kind of unusual sale pricing. So, I'm guessing that the $860 you're seeing is probably the first type of upgrade listed; it will only apply to SFO-TPE, and you may not earn extra PQMs/PQDs for it.

FYI: V is a discounted coach fare class -- not the lowest, but not a particularly high fare class either. The co-pay for a mileage upgrade is "only" $500 (plus 30K miles).

1. $860 is a great price.
2. If you buy it, take a screenshot showing the offer includes the SFO-TPE segment before clicking "purchase." UA IT is notorious for screwing these things up and you'll want proof what the offer really was.