Inflation

So, I'm about to go teach lessons now, and as many of you know, I commute because I can't teach lessons in my apartment... stupid landlady >:( Anyway, with gas prices as they are and the rising cost of renting an apartment, I'm thinking of raising my rates. I was thinking that a $2 increase per 1/2 hour lesson along with a $3-5 commuting fee would be acceptable... or should I say it's just a flat $5 for commuting? Either way, I know the parents appreciate not having to drive to me because I could technically teach @ CSUN and it takes time out of their busy schedules. So, it's a convenience for me to drive to them... one that I would gladly pay $5 for if I were a parent! So, what do you all think? How should I pitch my new price increase to the parents? When should I increase my rates? (I was thinking September) Give me some feedback in the comments box! :)