M vs B fare
 

I am looking at purchasing a M outbound, B inbound TATL ticket because both allow for upgrades for only 25k miles each. I don't need the flexibility afforded by a B on the outbound, so I was trying to lower the costs a bit (at the sacrifice of MQM).

I know that you should be limited by the more restrictive of the two. Is this the case even after I fly the outbound? I'd rather avoid a YMMV/HUACA situation should I wish to change the return.

It really depends on the particular fare rules. One thing: before you buy these expensive tickets, have you confirmed that an upgrade is available and how many miles it will require? I thought 25k upgrades went up in May.

I thought that each leg had its own fare rules. So if you have M outbound and B return, and you call to change only the return, it's governed by the B rules. The most restrictive rule applies to single legs of the trip (e.g. same-day A>B>C with a fare mixture).

When you purchase a RT ticket the most restrictive rules govern. It doesn't matter that you've flown the outbound or not. If one says change fee is $500 and the other says you can make free changes, you still have to pay $500 to make a change.

This has been the practice with RT/Multi-fare tickets for at least the past 20 years I that have regularly flown.

There are normally advantages to changing the return after the outbound has been flown but this isn't one of them.

Maybe this is why when buying directly from DL they tend to force the same fare each direction, so that the customer doesn't get confused about the rules?

HUH? I'm always offered different fare classes, including broken fares, on delta.dumb.

However, only certain fares are combinable in markets with RT pricing.

I think you better check on the miles required. That changed very recently (June 1st), the quote I was given for a B fare was 60,000 each way.

I confirmed only 30k each way for YBM.

I've used a GUC before on a fare with a stopover and it covered all legs. The agent was telling me that with miles I would have to pay "per day." Not sure if that's correct or not. :confused:

The broken fare problem is highlighted in the current T&Cs:

Any stopovers are governed by the fare rule, and additional mileage will be required for broken fares.

I'm aware of that verbiage. It would seem to suggest that a fare that allows a stopover should be covered with one mileage payment.

The ticket I was playing with was certainly not a broken fare.

Yes. The term is fare component.

The T&Cs also say:

Mileage Upgrade Awards allow a one cabin upgrade from the purchased fare.

Perhaps this will mean Y>W>J in the future?

Aren't sure on the future of things with the one cabin upgrade thing, but it certainly would be crappy. Currently that Y->W only applies for AF tickets to go from their economy cabin to premium economy. I am concerned about what DL will do with upgrades in the future once they introduce a real premium econ product for international however.

Anyway about your current upgrade, if the fare rule does allow a stopover then you should not need an additional mileage award for the upgrade. There could be another limit on the amount of time for a stopover allowed for use of mileage/GUC as well.

I can confirm that there's not a time limit on GUC stopovers, as I've had a stopover of many months covered with one cert. :D