Why does George agree to let Candy come with them to their dream farm ?

George agrees because Candy has money to invest.

Candy said, "I ain’t much good with on’y one hand. I lost my hand right here on this ranch. That’s why they give me a job swampin’. An’ they give me two hunderd an’ fifty dollars ‘cause I los’ my hand. An’ I got fifty more saved up right in the bank, right now. Tha’s three hunderd, and I got fifty more comin’ the end a the month. Tell you what—" He leaned forward eagerly. "S’pose I went in with you guys. Tha’s three hunderd an’ fifty bucks I’d put in. I ain’t much good, but I could cook and tend the chickens and hoe the garden some. How’d that be?"