As to the costs of scribing itself, I don't see it as a problem, either way. The relatively low cost of manufacturing items (scrolls, potions, wands and so forth) helps offset the cost from scribing, somewhat. Further, the gold cost for the wizard offsets the cost for magic equipment for the non-spellcasters, at least with relation to combat effectiveness.
In my main game, the party wizard has a BBB, in the beta game I run, the wizard did not, nor was I likely to let him have one...mostly due to the reduced financial levels of that game.