You can get lots of information from here on the Manx
http://manxgrandprix.org/index.html
And if you scroll down this page you will be able to get this years regs and the quailfiying times are in the regs
http://manxgrandprix.org/Competitors/Inforiders.html
23 minute is the quailifing time for the Junior and Senior it 25 minutes for a 400 in the Ultra lightweight
Thats about 98.4 mph and 94.3mph respectivly
On a 400 25 minutes is fairly easy............23 on a 600 can be a bit tougher you need to work at it and learn where you are going.
I've been doing the Manx since 1997...................never counted the total cost for a Manx but it must be over 4K given all the extra stuff needed nowdays.
You could do it for much less or you can spend much much more...............how much have you got and how fast do you want to go
I am an ambassador for the Manx GP................ see here
http://manxgrandprix.org/ambassadors.html
Scroll down and you'll find me.
I assume by your questions your thinking of trying the Manx ?
I'm able to help................learning the course or with getting entries organised.............I can help with a trip to the IOM off season including free accomidation and can also put you in contact with people who will help with travel
IF you can meet certain criteria.
Either way just ask and you shall recieve.
I'll PM my phone number to you if you'd like to chat ?