[Grammar] That would be interesting. Thanks,

[Oceanlike]

Is it a comma or a full-stop after the word, ‘interesting’ in the dialogue below? I’m inclined to put a full-stop.

The librarian asked, “Would you like to borrow a movie CD about the story? The book is currently out on loan.”

“That would be interesting. Thanks,” said Timmy. OR

“That would be interesting, Thanks,” said Timmy.

Thank you! :-D

 

[MikeNewYork]

I would start the sentence with "Thanks,".

 

[Raymott]

Assuming that you're not going to start the sentence with "Thanks", you need the first sentence.
The second would require a small 't'. But it doesn't work.
"OK, I'll take the CD, thanks." does work.