As a GM if I had decided that in order to limit the power of wizards that spells were going to cost more than normal I would definitely not allow anyone to get around that for free. And if someone told me 'the internet says you should do something different' I would laugh at them.
WBL includes the purchase of spells and also consumables such as scrolls, this does mean it is debatable if you should get slightly more than WBL to cover consumables etc but that is GM decision and varies from GM to GM.
The High level wizards in my capmaigns spend a lot of money on learning all the useful spells.
Your GM may well intend that you should join one of the magic academies it is likely that members can learn spells more cheaply, alternatively killing off enemy wizards is a good way to get access to spellbooks for free.
Blood transcription (http://www.d20pfsrd.com/magic/all-spells/b/blood-transcription/) can also help if you run into Sorcerors or Clerics(depending on their spells memorised).
Depending on your gm's interpretation you may be able to scribe scrolls with the help of a cleric/druid in your party and then learn the spell from that.
(Also just checking you are remembering the 2 free spells per level )
If you are very concerned about wealth then take craft wondrous item it saves you a fortune over the course of your career if you have enough downtime to use it. Craft Arms/armour can also help if your allies are willing to pay slightly above cost (or can just help the party if you are more mercenary ).
All of this is campaign and GM dependent
In theory, with WBL you spend the money on scrolls to be able to learn the spell. The scroll is used up, going with WBL you should get that money back at level up to again bring you back up to WBL. Of course...technically we should count the value of the spell in your spell book against your WBL, but it wouldn't be the inflated price.
Ultimately your just going to need to talk to your GM.
If they've raised prices, they're unlikely to allow any work around. But under a strict theory of WBL you should get that extra money back, eventually.
If I were in your shoes I'd assume that the GM has a reason for it. My first assumption would be that it's a story-driven thing and that there would either be ways to overcome it. Eg: befriending other wizards, joining an academy, looking into why there's a supply problem then going and fixing it (which may well be the story your GM has planned).
If it's not a story-driven thing and the GM thinks they're balancing things by having spells cost more, well, that's something you would have to ask them about.