I haven't seen too many premiums paid for sequential notes unless they're pretty rare (1937-Osborne or 1935, low numbers) and in UNC. Naturally sequential Devil's, and some of the rarer UNC asterisks of modified will command a premium, but seldom 1967 *B/M.
If they're asterisk N/O L/O or F/P then its more likely -- but then again not many collectors can afford (or see paying) over $100 per note. If there's 15 of them its unlikely they'd be the rarer kind and more likely they're *B/M. Since *B/M are so common you'd do well to get $20 a piece.