Never pay "WAR value," because it's set by the dumbest GMs ("winner's curse"). If you want to be a sub-.500 team, consistently overpay. What makes a good GM is recognizing value, any fool can pay the Fansgraph "market price."
I use $7M per expected WAR because if you're paying more, you can't afford a winning team (you don't get a lot of discounts from young players, because rookies and second year players tend to have low WAR as a group, see Franco, and by the 3rd-4th year, arbitration sets in and WAR becomes more expensive).
Question is what to expect from Hellickson?
His average was 1.5 WAR, but he was definitely improved last year.
However, no gain in velocity, no improvement in his changeup or control is likely, so there's little upside left, only downside.
I'd say 6 WAR over the next three years (and anything longer would be foolish) isn't unreasonable.
3yr/$42M would be a good deal, 3yr/$48M a slight overpay, anything higher or longer wouldn't be worthwhile.
The reason to resign him would be as an innings eater until the young pitchers mature, and then flip him.
Which means you'd want to structure a contract that's front loaded to make it easier to trade him.