Answer:
"I could just tell. Desperate for a new toy, are you?"
Step-by-step explanation:
Tommy had never seen or heard about kids buying something at Orson's Confectionaries that Orson assumes young people who wanted to enter the store are interested working there. The presence of the "Help Wanted" sign supports this conclusion. Mr. Orson may have also guessed this from Tommy's stammering after being asked about sweets.
Hope this helps :)