When to start B2 visa application?

[godu]

My parents are planning to visit me in USA next year, i.e. June 2011. So when they should start the application process? Is it too early if we try to schedule the visa interview on November 2010?

Thanks,
DP

[immihelp]

That is too early.

Start in Feb-Mar timeframe, if not later.

[godu]

Thanks for the reply.

We already paid the visa fees to HDFC bank. But I have not yet scheduled interview dates.

If I wait till March and then schedule the interview in March 2011, will the visa fees number remain valid?

Please help.

[immihelp]

Yes, for one year.

[godu]

Thanks again.

What happens if the visa fee changes by that time?