Tourney Structure - is this reasonable?

[Ace_W_Ace]

Heard about this NLHE tourney that someone is trying to put
together, but the structure sounded a bit steep (in favor of the host) to me. Just looking for some opinions.
Buy in $100
48 players
Payout 1st: $2k, 2nd $1.5k, 3rd $500, 4th-6th $100
1500 starting chips, blind go up every 20mins.
I believe this comes out to a $80+$20 buy in.
I'm not too crazy about the 4th-6th payout.
Seems like 4th should pay more than 6th.