You're right @Jeanne J the 3 letter prefixes are common for each note.
Billions of both the $1.00 & $2.00 were issued (& millions were saved). They would be worth face value to most collectors (but perhaps somebody here might like to trade)?
Take a closer look at the 2$ bill. If the two B prefix are different then there might be a slight premium as a variety Big B Little B. My eyes can not see a difference in the photo. The 1$ bills can get a loonie at the bank.