Sentence:  "They know our boats will stand up to their work," said Willison, "and that counts for a good <WSD>deal</WSD>. A low estimate from us doesn't mean scamped work, but just that we want to keep the yard busy over a slack time." 
Meaning of the word marked with <WSD> tags:  An indefinite quantity or amount; a lot ("now usually qualified by" (great) "or" (good)).