Max value for a well concealed hand

The limper is, well, a limper - 73/9 over 11 hands.

It's probably a mistake not to bet the turn. I don't mind a check, because I'm not sure what we're getting two streets of value from that didn't bet the flop, but I think perhaps it is a bet - interested in opinions on that.

Mostly though, not sure how big to make the river. I won't mention what I made it because I want to see what everone else thinks.

If a raise to something sensible gets called about 90% of the time (he's clearly bad), then raising to say $3 gets another ~$2.20 out of his 4x.

If a jam gets called about 30% of the time it extracts about $4. Is an estimate of a 30% calling frequency for a jam too optimistic?

What about something in-between? I am not sure I like anything in between - I either want to get called a lot with a reasonable sized river 3bet, or get a jam called often enough to make it higher EV, but I'm not sure he really calls say a raise to $6 much more often than he calls a jam.

Poker Stars, $0.05/$0.10 No Limit Hold'em Cash, 6 Players
Poker Tools Powered By Holdem Manager - The Ultimate Poker Software Suite.

BTN: $34.85 (348.5 bb)
SB: $4.75 (47.5 bb)
Hero (BB): $13.77 (137.7 bb)
UTG: $10 (100 bb)
MP: $15.06 (150.6 bb)
CO: $5.99 (59.9 bb)

Preflop: Hero is BB with 3 5
UTG folds, MP calls $0.10, CO calls $0.10, 2 folds, Hero checks

Flop: ($0.35) 3 A 2 (3 players)
Hero checks, MP checks, CO checks

Turn: ($0.35) 5 (3 players)
Hero checks, MP checks, CO checks

River: ($0.35) 5 (3 players)
Hero bets $0.20, MP raises to $0.60, CO folds

Hero raises to ???