Heighten Spell

[varusso]

OK I am sure this has been answered definitively somewhere, but all the searches I get are side-tracked threads or suppositions. I would like a definitive answer, not a guess, or "it SHOULD be this way".

Heighten spell says it will raise your spells to the "highest level spell" you can cast...does that refer to the highest for that CLASS or the highest for that CHARACTER?

EX:
If you multi-class spellcasters...lets say Cleric and Sorc. LvL 5 cleric spells, lvl 1 sorc spells...if you use Heighten Spell on the Sorc spells, does it remain at LVL 1, or does it raise to LVL 5, since your cleric side can cast that? The wording of the feat seems to indicate it would raise to lvl 5, but I want to be CERTAIN before I take it.

Also, I assume the increase in casting cost is proportional to the amount of levels raised. Is the formula known, or does it vary according to each spell?

[rimble]

Nothing between caster classes 'bleeds over' (well, except for spell points I guess). If you Heighten a Cleric spell it'd be Level 5, if you Heighten a Sorcerer spell it'd have no effect (since your highest spell level is only Level 1 already). This is one of the many reasons why mixing any caster classes is a bad idea.

I thought the tooltip for it said how much it costs...like 5sp/level or whatever...anyways, it's relative.

[varusso]

Actually mixing casters is just fine, so long as you do it with eyes open and full awareness of what you are trading off for whatever benefit you are receiving, as well as a clear idea of what "type" of character you want to build as a result.

For example, knowing whether or not a feat will work as expected when mixing those classes Thanks!