It appears that B&H has two used Pentax 28-70/2.8s right now. Vic
If you need speed, you will need to spend the $$ on a constant aperture 24/28-70/75/80 f2.8. Tokina's 28-80 is extremely sharp. Tamron's new 28-75 has been tested to be very sharp, and is less expensive. Sometimes KEH has used FA 28-70 f2.8s.
