It's obviously a lie. She has been extremely modest, tabloids still came up with those lies on her spending. Imagine if she wore Valentino, Oscar de la Renta, Chanel, hanging jewels all over herself like her in-laws, what kind of lies the press would come up with ?
Thats an extreme nobody is asking for and something the inlaws dont do every day. For the ordinary event they all wear professional, good quality fashion, something that Letizia is obviously lacking. The fact that Queen Sofia wears lots of jewellery is a personal habit of hers, same here, its not the diamond fleur de lys brooch every other day.
Its not that Letizia doesnt wear designer at all, its not all Mango or Zara on her, she does wear Burberry, Loewe, Prada (at least accessories) or Boss from time to time; no couture, but not exactly cheap either.
Letizia stopped wearing quality fashion a couple of years before the alleged reproach that her budget is 20.000 Euros a month and I still dont believe that she took the decision to stop wearing couture after marriage because of media pressure but because of a personal strategy: to deflect as much from appearance as possible by wearing neat suits with matching handbag and pumps, what has failed completely. Whatever Letizia wears makes the headline, nothing unusual for a CP, but I think she was aiming higher. Maybe thats the reason for not putting any effort anymore into her appearance, because in the end it doesnt matter. The mags will come up with the usual headline, how stylish, how trendsetter-ish, because there is nothing else to say.
And because we have never seen Letizia dressed up like her inlaws in Oscar de la Renta, Valentino or Chanel it is still your personal assumption that the press would crucify her for doing so (hard to imagine in case the Queen wears similar couture at the same event).
It was a big mistake to stop wearing couture like Armani etc on high profile events; now, with the economic situation its almost impossible to start again. What I find shocking is that even the professional hairdo seems to be out of reach for a while now on state occasions. Since I havent heard that Letizia got mobbed by the media for styling her hair it seems to be her personal decision to stop doing so out of disillusion, see above, as little effort as possible.