United MileagePlus (Consolidated) - Any reason to not buy a refundable ticket to hold a specific Y+ seat?

I'm traveling to Europe in September and am booked in Y with an upgrade pending. If I knew for sure that the upgrade would not clear, I'd gladly pay the $ to grab one of the bulkhead E+ seats prior to check-in but, obviously, I don't want to do that and then end up forfeiting the E+ money if my upgrade clears.

Aside, perhaps, from karma, is there any reason to not purchase a fully refundable fare and reserve the bulkhead E+ seat I'd like and then, at T-24, cancel the refundable ticket and hope I can slip into that bulkhead seat (as 2P, at that point I'd actually be able to move to E+ for free)?

How long, in people's experience, does it take for a seat to open up once the person holding that seat either cancels the reservation or changes their seat?

Thanks.

....
Aside, perhaps, from karma, is there any reason to not purchase a fully refundable fare and reserve the bulkhead E+ seat I'd like and then, at T-24, cancel the refundable ticket and hope I can slip into that bulkhead seat (as 2P, at that point I'd actually be able to move to E+ for free)? .....there is more than negative karma, the airlines specifically consider this ticketing fraud -- so there is a (likely small) potential of more severe consequences.

Additionally in past threads on a similar tactics, the FT community has been polarized on this -- since you are potentially blocking another passenger from accessing that seat.

And there is the question about the ethics of such action -- again the FT community tends to split on this.

IIRC one used to be able to get the E+ fee refunded if an upgrade cleared. A strict reading of the terms on the website seem to indicate this is still true.

What is the refund policy for Economy Plus®?

Economy Plus purchases are automatically refunded in the event of flight cancellation, change to a different flight, or when travel is not completed in Economy Plus seating. In all other cases Economy Plus purchases are nonrefundable.

There was even one FTer who managed to get it refunded on an op-up...

It's not very nice to buy a ticket solely to make it impossible for someone else to buy the space.

You can probably get away with it once, but you shouldn't do it -- (1) depleting a common good eventually leads to tragedy, (2) if you do it more than once you might get caught. (If you wanted to get away with it once, you would buy a ticket in the name of a spouse or family member and then, oops, plans changed, good thing it was refundable.)

If what you're doing matches a pattern that the airlines see commonly or that a computer can easily detect, you might get a nasty message from someone with the "revenue protection" arm of the company asking you to pay them money or be banned from the airline. You might also get sued if what you do breaks the contract of carriage.

For discussion on various versions of this strategy, see the US Airways forum thread http://www.flyertalk.com/forum/us-airways-dividend-miles/1361135-booking-phantom-fully-refundable-ticket-ensure-empty-seats-next-you.html and the AA forum thread http://www.flyertalk.com/forum/american-aadvantage/1107829-pax-caught-trying-hold-cancel-refundable-c-seats-attempt-secure-swu.html. (I think there have been other FlyerTalk threads about holding premium-cabin space, then refunding it, to get your upgrade to clear … can't find the other one I'm thinking of now.)

Thanks, all. Appreciate the feedback and I think I'll just pay the $139 and hope for an upgrade and refund.

Aside from everything mentioned, booking a second ticket on the same flight in your same name will likely get one reservation canceled as a duplicate. Not sure how the new UA handles this, though I suspect they have some sort of sweep to detect this - PMUA definitely did.