In the episode Off to Hollywood, Andy worries about having enough money to go there. However, if he needed extra cash all he'd need to do is go up to the attic and track down some of Opie's old toys to sell.

You see In the episode Quiet Sam (which incidentally was the first episode written by TAGS writing legends Everette Greenbaum and Jim Fritzell), in the scene where Opie, Andy, and Aunt Bea are talking about Nat Pike being wise for his age, Opie is playing with a toy team locomotive. That toy steam locomotive just so happens to be a Weeden Dart, a live steam locomotive that is very popular with model train collector crowd. Given the good condition it's in, I would be willing to bet that if Andy found the right buyer he could make five thousand dollars in today's money by selling it. The Taylors would have more than enough cash for any Hollywood adventurer.

How much do you think that locomotive would've been worth back in the 60's? If it belonged to Opie then I seriously doubt that Andy would even consider selling it unless it were absolutely necessary.