I seem to remember (and it's a few years since I did this, so happy to be corrected) that even if you move to a more expensive part of the ground you don't actually pay any more for your own ticket. Unless it was bundled into my ST direct debit without me noticing.
They'd be much happier with the Man U solution then.
Although there is some sort of implication in terms of loyalty bonuses if you try and do it twice. I'm not sure how serious it is as I don't know what the loyalty pot is and I don't care enough to try and find out.
I don't see anything to suggest that it doesn't include tickets that have been bought and simply returned by the original purchaser. The page I'm reading refers to "Domestic Away Games" in general, not cup games specifically.
Hold onto your hat, because your head might explode when I tell you...
Man U have a returns policy as well:
"If any tickets are returned to the club to be sold, they will go on sale online here. Tickets released in this way after the ballot can be purchased by supporters who were unsuccessful in the original ballot only.
We do not operate a waiting list for...
Since I'm sure you're still really keen to get an answer to this question Wozza, clause 7.11 of the Spur's Membership Terms linked to above relates to resale/reallocation of away tickets.
Briefly, if the original purchaser tells them they can't go the club will resell it themselves to somebody...