New tool: spell maker
A long time ago in a forum far, far away, a question was asked. The time has now come for an answer.
Pretty dramatic, huh?
To elaborate: yes, there now is a spellmaking tool for Morrowind.
You can select up to 8 magic effects for your custom spell and set their range, magnitudes, durations and areas and see how much the spell will cost. You also get a detailed effect analysis to go with that.
If you also enter your character's magic skill levels, willpower and luck, you get to see their chance to successfully cast the spell at full fatigue and no Sound effect bothering them.
The spell maker has two modes: a vanilla mode and a mode that uses the increased cost for spells with an area of effect, courtesy of the Morrowind Code Patch.
As always, there are probably some bugs left to clear out, so if you find any incorrect calculations, let me know and I'll do my best to fix them.