Alright, my sis got her lappie at SP for 1.3-1.4k.
Specs:
2.26GHz Core 2 Duo
3GB or RAM
160GB of HDD space, I think
And probably what I would always love in a lappie.......
A Dedicated GPU.
ATi Radeon Mobility HD2400XT with 256MB of RAM. Think is
DDR2.
This was about a year back, I think, so for the same price, you
should be able to get a better lappie.
Answers to most of your questions:
1. Your school will sell the laptops at cheaper prices, say,
around $300 cheaper? They also will give you a bundle or a package
along with the lower price. For example, at NUS IT Coop, an Acer
4930G with 2.53GHz C2D, 4GB of RAM, 512MB 9300M GS goes for
1.7-1.8k. Outside, 2k+.
2)That will depend on the school or poly in question. Some may
have custom software they will install on your lappie, some don't.
Some will install XP on your lappie, some wont put anything on your
lappie. Most of the time, it will be your course lecturer asking
you to install these software.
3)There are people who already have laptops when they enter
poly, and each course may have different requirements. Im sure if
you have a lappie when entering poly, it should be able to run the
programs well enough. Anyone here still have P III Moblie
laptops?
Not too sure, cause not in poly. 
lol
processor is what model 1
poly always put the numbers instead of model number to fool
computer noobs
cheap la, but service center many many
