Yes, belves seem like the type of folks to let themselves go far into debt.

However their city is maintained and built mostly through magic and last I checked magic is free. One of the few references to actual manual labor is Worker Mo'rrisroe who has been clanging his silver hammer in that back room in Silvermoon for years now.

Hair products aren't cheap in Azeroth either. I mean, priorities! /hair-flip

Magic is free? Doubtful, and besides the point. Magicians are skilled professionals with years of schooling and training (ie, their time is valuable), and spells have to be maintained or replaced. And as we all know, working magic degrades the equipment you use; that's a cost, too. None of which even touches on the reagents required...

Thing is though, Jil, how does the fact that the blood elves have been rebuilding their city necessarily follow to them being in debt to Orgrimmar? I mean, it's not like we see orc labor being used to restore Silvermoon, or orcish brigades reinforcing Quel'thalas.

As far as we know, the blood elves have been paying for the restoration effort out of their own pocket, entirely self-contained, with their own people doing the work, which means the money never leaves Quel'thalas. And there's certainly no word of them taking out a loan from the Bank of Orgrimmar to pay for it.

More likely, Garrosh knows that Silvermoon (a city gilded in gold and precious metals) is a far richer place than Thunder Bluff, and so demands more cash out of the elves than he does the tauren.

You don't think the orcs are GIVING away all those trees they clear-cut out of Ashenvale, do ya?