If I were you, I would research a bit more into the function of the Transaction Advisory Services group in the LBO process and see if it interests you. I work in banking (though not the “investment banking” you’re thinking of) and we receive the TAS reports as part of our diligence in evaluating EBITDA (figure used as a multiple for purchase price as well as leverage). While it will give you great insight into accounting/financial statements and may give you some connections with ibanking analysts/associates and PE associates (your points of contact when reporting findings), it is definitely not investment banking.
As far as interviews… remember, most people go to bschool for a career change; you’ll be competing for interview slots against engineers, folks with liberal arts backgrounds, non-profit, and of course consultants and bankers. Investment banking is not brain surgery. If you know your way around excel you’re well ahead of the gang. Banks will be looking for articulate, motivated people that can pick things up quickly and can handle 80-100+ hours a week.
As far as starting salary... No clue how the supply/demand shift will change comp levels with the current recession (assumption on my part that there will be less ibanking jobs in the next 1-3 years), but I assume banks offer market compensation for all interns/recent MBAs (no matter your background).
As a side note, E&Y probably will give you lots of flex room to negotiate your salary. Your hourly billing rate compared to what they pay you is ridiculous. If it is a role that interests you, I'm sure you can get them to match the Accenture offer - if $$ is a deciding factor. Again, just my opinion.