The plain old Shooting Chrony for ~$100 is good enough for many of us.
There are better ones. They usually cost more. But, most are subject to some of the same issues.
By all means, get the best you can afford.
But in the end, the chronograph doesn't make your rifle shoot straighter or your bullets faster. They do give you some additional feedback for dialing in effective loads more quickly. And, for developing useful trajectory data. ...especially for getting on paper/steel at long range with new loads.
-- richard