I think that regardless of minimum wage, most people perform services for goods, and if they cost of those goods goes up, the wage they demand for their services will go up accordingly. I don't really see raising base salaries having much of an impact on the economy, at least in the long term. A tiered structure would be different, though, because it wouldn't necessarily raise the cost of all goods. It would just be a good way for motivated young people to find work and propel themselves to successful lives. It would also provide incentive for people with crappy jobs to either do well enough to make themselves worth the incremental raise the minimum wage would dictate or further their education/trade skill so they can work for more than minimum wage anyway.
I really think that way too many people are looking at Walmart and fast food jobs as career paths rather than just temporary jobs to work until they can find something better.
If forcing employers to pay employees more doesn't raise all goods, then clearly you can acknowledge it raises the price of some goods - which in turn, somewhere down the line DOES affects all goods. That's how it works. Where do you expect that extra money to come from?
How does a tiered wage motivate people to better themselves? Are they not smart enough to realize that there are jobs out there that pay better than Burger King without tiered minimum wages? Isn't what you're proposing exactly like how the economy works naturally? More skill has more pay? Because if it didnt, who in the hell would work somewhere that required more skill if it didnt pay more?
What exactly are you trying to accomplish by raising the minimum wage? If you really think too many people look at Walmart and Burger King as careers, what's the problem? Do you not like buying crappy things really cheap? Do you think these people are capable of commanding a higher wage, but don't for some reason?
The truth is, some people and some jobs are only worth $1 an hour. Which isn't actually all that bad, because it produces cheap products and people that are typically unproductive, because they're not skilled enough for minimum wage, can actually get a job - earn money and buy cheap crap.
It's win/win and it's exactly why so many companies outsource their labor to other countries.