Split the money or take it all?

[Willluck]

Lets say you and a group of 9 other friends have a weekly $100 winner-take-all NL tourney. Each player starts out with t1000. Every other player beside you is weak. They limp 3 times more than they raise, and they occasionally make bad bluffs. their avg VPTIP is about 38%.
1st question: How much would you say your $100 buy in is worth?

2nd question: It comes down to heads up play, one night and you take a bad beat from an average player. so now the chip count is You: t1000, Him: t9,000 and blinds are only 100, 200. Now, your friend offers to split the $1000 grand prize with you 50/50. So the question is: Which has more +EV, to finish the tourney or take the $500?