Answer:
Tristan will have more buying power and a better standard of living. The ripple effect of this on his financial decision will be that he will spend more.
Explanation :
Tristan increased income will affect his financial decision in the sense that he will have more purchasing power of goods and services, his standard of living will probably improve and consequently affecting his financial decision.
He will probably move to a neighborhood with safer security, reliable water and power supply. The ripple effect on this new found good life is that his financial decision will always make him spend more to sustain this life style.
It should also be of note the an increased income does not necessary translate to the want or need to live in luxury.
Comparing the new income with his previous budget when he worked part time prior to his degree, Tristan at this time would have be able to achieve sustainability and more purchasing power through proper investment.