On a one-minute single-boss fight the benchmark set prices a percent of spell hit at 14.5 Spell damage, a percent of spell crit at 12.6 and a percent of casting speed at 10.4. A point of Fire damage counts 1.00 and a point of Intellect 0.22. The weights start from that set, so they price the next point you add, not a whole new set.
Per point
- Fire damage1.00
- Spell damage1.00
- Intellect0.22
Per 1 %
- Spell hit14.5
- Spell crit12.6
- Casting speed10.4
Spell hit
Until Forever publishes its spell table, our simulator uses Classic's: a level-63 boss resists 17 % of your spells, and 16 % hit leaves only the 1 % nothing removes. 
Elemental Precision gives Fire spells and the bolt 5 %, and this set adds 3.0 % from gear. A miss costs more than its damage: no Ignite, no Heating Up stack, and on the longer fights no roll for Fingers of Frost. In Forever an item's hit counts for your spells as well as for melee.
Spell crit
A Frostfire Bolt crit deals 200 % with 
Ice Shards, and 
Ignite adds 40 % of that over four seconds. A Fire Blast, Scorch or Pyroblast crit deals 150 % before its Ignite. Spells roll crit apart from hit, with no penalty against a boss in our simulator, so there is no cap. The sheet shows 19.6 % before 
Critical Mass adds 6 % to every Fire spell.
Casting speed
Haste shortens the bolt's 2.5-second cast and every Scorch and Pyroblast. Pre-raid gear has almost none: the one-boss sets get 1 % from Minor Haste on the gloves, which Wowhead still lists as PTR only.
Fire damage, spell damage and Intellect
Fire damage counts the same as spell damage, because every spell in the one-boss rotation is Fire and our simulator reads the bolt's Fire damage. Frost damage gets no weight at all: the engine gives the bolt Fire damage only. Blizzard says the bolt uses the higher of your Fire and Frost damage, and with this set's Fire-only gear that is the Fire figure anyway. Intellect buys mana and 1 % crit for 59.5 points, so its weight follows how short of mana you run: 0.22 on one minute, where you never run dry, and 0.60 on two, where the rotation's Evocation line never comes up.
On every fight
Spell hit tops the list on all six fights, with crit next on one boss. On three bosses every rating gains on spell damage, because Flamestrike draws little from spell damage. Casting speed comes second on a one-minute fight against three bosses at 25.1, and on a three-minute fight against three bosses the mana stats count: Spirit 1.16 and MP5 1.17.