Maybe it's the typical notation that's throwing you off, BamBam - here's how I think about it:
Advantages are listed as +x : the positive sign reminds you it is a real-cost increasing effect
Limitations are listed as -x : the negative sing reminds you it is a real-cost decreasing effect.
However, in their respective formulas, they're both treated as using their absolute value. (Look at many examples in the books to see this in action.)
Yes, the formula is stated as Active Cost / (1 + total value of limitations). And all the individual limitations are listed with negative values like -¼, -½, -1, etc.
However when you put them in that "total value of the limitations" use their absolute value: ¼, ½, 1, etc. The literal wording of the text in the rules doesn't say absolute value; but it does say "total the Limitations as positive values, even though they’re listed as 'negative' numbers" in the paragraph above the formula. (6E V1 page 365)
So a power with two -¼ limitations winds up in the formula as "Active Cost / (1 + ½)", Thus a 60 active point power comes out to a 40 real cost. Or with a -1 limitation, a 60 active point power comes out to a 30 real cost. (It has to work this way, or a power with limitations literally totaled as negative values that totaled to less than -1, such as an OAF (-1) with 4 charges (-1), and thus a literal total of -2, would actually cause a power to have a negative real-cost total.)
The use of absolute value and structure of the formulae effectively makes limitations have the same proportional effect as advantages with the same value: for example, a +1 advantage doubles the active cost of a power, 20 active points become 40 real; while a -1 limitation halves the cost of a power, 40 active points becomes 20 real. A +½ advantage adds "half-again" to the cost of a power, 20 active points becomes 30 real; while a -½ limitation cuts it by a third, 30 active points become 20 real. Proportionally, it works.