Other than price and yards, what is the difference between 25yds of 25lb Seagar florocarbon leader material (approx. $10) and
200yds of 25lb Seagar florocarbon fishing line (approx $30).

Both had the same diameter .019"

$10 for 25yds of line seems like highway robbery (so does $30 for 200yds, but not as bad)

Other than price and yards, what is the difference between 25yds of 25lb Seagar florocarbon leader material (approx. $10) and
200yds of 25lb Seagar florocarbon fishing line (approx $30).

Both had the same diameter .019"

$10 for 25yds of line seems like highway robbery (so does $30 for 200yds, but not as bad)

Not sure about here... but SOMETIMES leader material is a little thicker/stiffer than line. Either way 25Lbs seems VERY light as a rule I use 50. Also I have switched back to mono w/NO discernable difference except in my pocket.

I go with mono, that stuff is to stiff and I like how supple mono is, Triline
Big Game 50 pound from surfcasting-rhodeisland

It's likely that the tippet (leader) material has a much tighter QC to keep the break strength to an exact weight. This would be needed to qualify for an IGFA record, I believe.
The line has a much wider range of diameter (accross the whole spool) and a wider break strength range.

Peter
aka: Norgetrol