Thanks for the earlier posters who covered most of my points before I had the chance to revisit this thread. I'll add that, other than some flights on Sundays, Mondays, and Thursdays that are the most popular for domestic business travel, the rest of the flights during the week likely require discounting to some extent to fill the J cabin. Besides, OP's fare is ticketed in V, which suggests that the flight is either lightly booked or probably will not reach a critical point of overbooking. If UA can generate $600 from a V bucket right now (from the fare basis, at least 30 days in advance) with so many seats still available to sell, IMO that's a win-win for both UA and OP.

OH SNAP! I've always ignored the 'C' icon because it says "If you would like to also see the Booking Class Table for a secondary airline, enter it here."

I always thought that meant if we, for some reason, wanted to see the booking class for OAL, not UA since UA was already shown.

Thank you!

Indeed, you can also see the booking class for OAL, which is useful when buying a multi-carrier through fare. For example, if you were flying, say, NYC to SGN, UA partners with a laundry list of airlines on the last leg; here's the first (of 12) routings for the cheapest K fare on the date I searched:

If you wanted to know which fare class the last leg would book into on SQ or BR or CX or whatever, you'd enter that airline when you clicked on the 'C'.

I'm still curious how you bought this fare in the first place.

Is it possible that it was originally on a single-class aircraft (J0) and then later switched to an aircraft with a first class section (J9 P0)?

I don't think single class planes fly SFO<->LAX on ua/uax.

OP is not ticketed in 'V', he's ticketed in 'P'. Despite the fare basis code starting with V, this is a P fare. The V fare basis just means there is a dual inventory check and there must be inventory in both the coach V bucket and the FC P bucket to purchase the fare. Purchasing this fare will pull from the P bucket only, and not the coach V bucket. Flights are generally pretty lightly loaded more than 30 days out because few business pax buy their flight that far out.

Maybe one got fat-fingered into the schedule for a brief period, though.

Fare is still available, last I checked.

well, dates would be useful

OK, so I figured out what's happening.

In most markets, VAP30UPN would, in fact, require inventory in V along with the prime booking class (P, in this case). However, in EWR/LAX and EWR/SFO, UA has published this fare without the secondary inventory check: you can book VAP30UPN on any flight that has P available, assuming you have a 30-day advanced purchase.

Compare the booking code data for VAP30UPN, earlier in the thread, with the similar V-FN fare on AUS-SFO:

Note WHEN V AVAILABLE. OP's fare doesn't have that.

The key to the mystery is that when the through fare is very expensive, UA will check mixed class fares also, which necessitate using divorced inventory data. UA's married inventory for OP's flight is J9 C9 D9 Z1 P0 Y9 B9 M9 E0. However, there's P space on the SFO flight, when divorced from SFO-LAX, and UA finds the mixed-class price using the VAP30UPN fare, because the only booking class requirement is P and Y.

You can actually simulate this any time you want with a multiple-city search. If there's P on the EWR-SFO leg, you can connect it with any SFO-LAX within 4 hours in Y. (It also works for EWR-LAX-SFO).

I don't know if there is a distinction betwen an instant upgrade fare (VAP30UPN) and a sell-up fare that you brought up for SFOAUS, which books into revenue Z. Perhaps with instant upgrades, not all flights in the combination, particularly the less-significant one, needs to be P>0 for the booking engine to offer/sell.

Well, it's specifically allowing this because the VAP30UPN fare doesn't have a V inventory restriction, and it delegates into Y, not V, when P is not available. And it's showing up in the search results because it's the cheapest available fare: it's cheaper than a coach ticket on that date.

That used to happen regularly, but it mostly disappeared when UA went to differential-based pricing. But the EWR-LAX fare table is really messed up, at least for that date. You've got the cheapest available fare: VAP30UPN, at $644 + tax, which books into P with no inventory restriction and a 30-day advance purchase. The cheapest available Z fare is YAZ21UPN, at $1094 plus tax and a 21-day advance purchase. And, if you wanted to fly economy on that date... you need to go to MAA0AQEY, at $1124 plus tax. Admittedly, it's refundable, and the others aren't, but that's still a pretty hefty penalty.

So, these fares are written as if they use differential pricing, but they're missing the inventory restriction that makes the differential work. Thus: business class cheaper than economy. (And even if they had the inventory restriction, the YAZ21UPN fare is way out of sequence).

That's a good point. Perhaps the real price differential lies in the amount of competition in the NYC-California markets versus, say, SFO/SJC/OAK-AUS. Because of the higher competition in NYC-Calif., lower-bucket restrictions are thrown out the door in order to capture a higher fare.

As for the economy fares, perhaps they are deceivingly high because you're only searching for oneway fares. The lower oneway fares in the tariffs currently do not extend to travel in December. However, roundtrip/excursion fares are much more reasonable and represent a significant discount from VAP30UPN as they are expected to be.

The p.s. fare table pretty always been non-differential, despite using the strange basis letters.. I don't know why they do that. It seems like V- are the deep discount B6 matches, H- was a mid-tier offering, and Y- is what they would "like" to offer (used to be a YAP21UPN at a laughable $1,000 or so).

The strange thing here, though, is that the fare is being delegated on the SFO-LAX segment instead of a higher through fare pricing. That normally only happens when the second segment is J0.