You should be allowed to trade gold for a 1:1 disenchant/enchant like once a week or once a month. Or there should be a quest you can randomly get (on par with the rarity of the 100 gold quest) that once completed, allows you to disenchant any one card for full value. I think it would really help introduce new players to the game whom feel that acquiring even the most modest collection to be even slightly competitive, insurmountable.
Imagine if once a week you were allowed to trade 1 common for another common, straight up, one rare, one epic and one legendary. I think that would be amazing. Personally I don't need it, my collection is pretty complete, but I just opened my 3rd Bolvar last night and was thinking how much it must suck in particular for a new player to have that happen. They get so excited, and then it's wasted because of the atrocious disenchant/enchant ratios. Plus it would add a lot of excitement and depth to quests if you chose to do it that way. It would be like "Win 1 game with each class...Reward: Disenchant any 1 card for full value." It would exclude goldens.
Would such a thing really be that bad for Blizzard in terms of people paying for product? I doubt it, in fact I think it'd make players spend even more real life cash, because they'd have at least some small hope that they could acquire a collection with a little time, or at least a couple decks of their choosing.