I'm leaning towards Yes on this but simply because I can't see how it would negatively effect anyone...
Initial reaction:
My main reason for liking it is the fact that I can see it as a nice gold sink... however... I'm guessing that's highly unlikely. For the record, I love GvG...
Here's my logic (again... could be flawed):
Attacking Guilds... won't they find this to be useless? You can see in the GL who attacks and see the results. *scratches head* Why would you spend more gold for this option?
Those that farm GvG (tongue-in-cheek) definitely wouldn't need it.... multie accusations aside.
Defending Guilds (and here I'm assuming somebody pays for it).... Not only do I think they don't need it... but I highly doubt they'd be willing to pay for it.
Keep in mind that I like GvG, I'm 100% for a gold sink and I can't see a negative aspect to this... except...
I don't really fathom any substantial benefit to the game and FS Players in general coming from it, especially after that... uh.. HCS suggestion on limiting levels... which leads me to...
I'd much rather like to see HCS spending their precious time on recent endeavors and further ones that I think are more important to the game as a whole. Again, that's not a knock at GvG... and I won't get off topic.
That said, and trying to remain on topic... I don't think this suggestion would fix GvG or make it more interesting in any way, shape or form.
SUMMARY:
Possible benefit: Gold sink?
Negative: waste of HCS time.
REQUEST:
If you have some insightful input... which directly responds to my doubts, feel free to pm me in FS once you've posted it.