Oh if the refunding idea would mean people will vote less than usual to obtain items, why not try to add something useful to vote for, like Ygg Berry Tickets, EDP Tickets, other consumable items etc. which will be made tradeable.
A x amount of Vote Coupons = x amount of [insert Item Name Here]
Like for example, 50-60 Vote Coupons will let you buy 100 Ygg Berry Tickets or 20 EDP Tickets. This idea will not spoil the idea of hunting those items since you'll have to vote for about 25-30 days for a few items. It will not be a source of another income or a cause of massive increase of supplies existing in our server since this items are mostly in demand, instead it will become another option for voting.
Seeing those who already have Fallen Ghost/Flower Aura + Bell Ribbon + Any Headgear that they are already contented with would likely vote lesser or none at all. But with this option, it would encourage them to vote again and again since 100 Ygg is not that much, but will be a bit of help for people who loves PvP/PK'ing/MVP'ing.
I could only think of consumable items that will become an only tradeable vote item because uhh, they will be consumed after all. I'm not suggesting that Vote Coupon or other Vote Item should be tradeable, only these consumable ones.
Again, this is just my suggestion/idea. I've already met this kind of condition from another server, and I see people try not to miss even a single vote. So feel free to comment/suggest.