A very good entry-level chronograph is the ProChrono Pal. With a little shopping they can be purchased for under $100.
Mule Deer's certainly right about the prochrono pal, but the prochrono digital which is the next model up from the pal & has more features can be had for under $100 also off of Amazon. $99.31 with free shipping.
http://www.amazon.com/Competition-E...mp;sr=8-1&keywords=prochrono+digital
