Rounding up or down?

[WBL]

If I find a magic site which gives me a 20% reduction to Thaumaturgy, and cast those augery spells there, will it cost 1 gem (half price, 20 reduction rounded down) or 2 (full price, rounding up)? Are all reductions/bonuses rounded up or down in the same way?

[Graeme Dice]

Originally posted by WBL:
Are all reductions/bonuses rounded up or down in the same way?

I am fairly certain that all such bonuses are rounded down.