looking for mathametical system for beating cash give-away-draws?

[arabie]

In neteller, you earn points that you can use to enter cash-draws. I've got 31,500 points. There are three draws:

1) Prize: $500
# of current entries: 48,860

2) Prize: $1000
# of current entries: 31370

3) Prize: $3000
# of current entries: 50670

Now, you can buy as many entries as you want with the points you have any combination of ways. My math is a little rusty, and the way i'd think to solve this would take me quite a while, so I was hoping one of you guys could help me out. I'm just looking for the best way to allocate my points. Another option, which can be answered seperately, could involve waiting to aqcuire more points and using them all in a later draw. Thanks a lot in advance to whoever takes the time..

[Lost Wages]

EV(in units of $/1k NETpoints) = Prize/Entries * Entries/1k NETPoints

1)Prize: $500
# of current entries: 48,860
Cost to enter: 1000 NETpoints

EV = $500/48861 * 1/1 = $0.010/1k NETPoints

2) Prize: $1000
# of current entries: 31370
Cost to enter: 2500 NETpoints

EV = $1000/31371 * 1/2.5 = $0.013/1k NETPoints

3) Prize: $3000
# of current entries: 50670
Cost to enter: 5000 NETpoints

EV = $3000/50671 * 1/5 = $0.012/1k NETPoints

So your best "bet" is #2 where your 31,500 NETPoints are worth about 41 cents. That assumes that your utility of money function is linear, that is, that you value $1000 exactly 2x $500 and $3000 exactly 6x $500.

Lost Wages