Get a plow for Mr. Smith.

Get a plow for Mr. Smith is a side quest in Fallout 2.

In Vault City, behind Cassidy's bar and Dr. Andrew's Clinic with the half working Auto-Doc, there is a stagnant family with neither the resources to leave town, nor to earn their sustenance.

Speaking to Mr. Smith will reveal a possible way to help them earn a living; "Happy" Harry has a Plow for sale, which would make farming much easier. Happy won't let the Plow go for the goodness of his heart, though. 800 chips, up front. A Barter check will reduce the cost to 600. Buy it when you've got the funds.

Rewards
Tell Happy to deliver it to Mr. Smith for a Desert Eagle .44 and 250 XP. If you get greedy and ask for a reward from Smith, you'll only get 100 dollars and the XP. Since an unloaded Desert Eagle .44 is worth $800, it's probably better to be nice.