Table is primarily full of competent regs, with seat 4 and 5 the only real spots on the table, just looking for help on the math here, if you have any comments the hand itself those are welcome too.

Hero (550) is viewed as somewhat LAGGY, have won a few pots in the last orbit without showdown (V1 is likely not concerned with my image)

V1 (seat4) (350) is an older gent who plays his hand face up, loose pre, willing to commit $ OTF and release on later streets without much qualm. Easy spot to semi-bluff and capitalize on his FE or get paid big when the draw comes in.

V2 is a good LAG, we have mutual respect and pretty much stay out of one another's way.

V2 staddles on the button

V1 limps SB.

Folds to Hero, who raises to 21 w/ QT in Lojack.

Folds to button, who calls.

V1 in SB calls.

Flop (60) J96

V1 checks. Hero bets 35. V2 folds. V1 calls.

Turn (130) T

V1 bets 75.

Hero?

My question is how much do we have to win on the end to make this a call if we assume V1's range is primarily sets and two pair?

Having to call 75 into 205, hero is getting ~2.7-1 in immediate odds.

Assuming 8 outs against the majority of V1's range, Hero has 18% equity, needing 4.5-1 to break even.

4.5 - 2.7 = 1.8

1.8 * 75 = 135

Adjusting for those times that V1 already has a straight, or those times where Hero improves to still second best and loses more, would it be accurate to assume that Hero must win $185 more in order to breakeven?

When u hit your str its going to put a oneliner out there so i think your io actually diminish significanlty...

I think your read is murky. Is v more prone to making folding errors or calling errors. Your decision whether to semi-bluff is predicated on this and board texture notwithstanding it's usually not both. As pointed out when you hit any value bet will be extrely polarizing. If v is the type to payoff this river when you hit its unlikely that you have much FE on an earlier street.

Excellent answer to a maths question I know

So what I do is this when considering implied odds: If you are 4:1 against just multiply the call by 4 and subtract the current pot. That's how much more you need in absolute dollars to make the call break even.

So in your case 4.5* 75= $340 (I round to $5).

340-205= 135.

Can you get v to call more than $135 OTR when you hit. Again considering what the board will look like.

As for discounting for coolers etc. I usually reduce my out count when calculating my odds. So if 2 straight cards bring a flush i discount one of them then I might discount another if I think has redraws in play etc.then my odds reflect that risk to some extent. So you might wind up at over 5:1 or w/e.