River call with A high: Standard or Burning Money??

[ajmargarine]

Villian in this hand is very high on the scale of donkiness. He has all the tricks. Opening for 20BB preflop, pushing preflop, minraising a PFR, etc. On flops he is capable of leading with a donkbet, then when raised, pushing. He's led for $15 with a $3 pot, capable of firing 2 and 3-barrels, betting with air, betting big with any part of the board, betting/raising his draws, etc etc etc. He is SB. We both have ~$150.

.50/$1 NLHE Full Table 8-handed.

Preflop: Hero is MP1 with A [img]/images/graemlins/heart.gif[/img] K [img]/images/graemlins/heart.gif[/img] . SB posts a blind of $0.50.
UTG calls $1, 1 fold, Hero raises to $5, 3 folds, Villian calls $4.50, 2 folds.

Flop: ($11.50) 9 [img]/images/graemlins/heart.gif[/img] T [img]/images/graemlins/spade.gif[/img] 3 [img]/images/graemlins/heart.gif[/img] <font color="blue"> (2 players)</font>
Villain bets $4.20, Hero calls.

Turn: ($19.65) 3 [img]/images/graemlins/club.gif[/img] <font color="blue"> (2 players)</font>
Villian bets $4.80, Hero calls.

River: ($28.75) 2 [img]/images/graemlins/club.gif[/img] <font color="blue"> (2 players)</font>
Villian bets $25, Hero calls.

Smallish flop and turn bets, a paired board, a big jump in betsize on the river...easy call? Comments on all streets appreciated.