Campaign experience impossible to earn as a level 7 mage?

I was looking at options for spending some time and money in downtime to earn a little extra experience and I noticed that it doesnt seem possible to break the gp threshold (2500) through conventional means as a 7th level mage.

Researching the most potent 4th level spells available to the 7th level mage costs 4000 gold and 2 months or 2000g per month.

Creating 4th level scrolls or potions costs 2000 gold and 1 month.

Neither of these options exceed the threshold of 2500g

Are precious materials the only option? Should the greatest return be scribing four 1st level scrolls per month. Each of them etched into a 10,000 -30,00 gold bar. To instead earn 38,500 - 118,500 experience per month.

It feels like there should be some middle ground between zero and massive. (If you can even spend precious materials on scrolls)

Or am I just missing something?