The newest Sandisk player is the Clip Jam. It is listed as having 18 hours of battery life. The Sandisk Clip Sport is listed as having 24 hours of battery life, and has a larger display than the Clip Jam. The Clip Jam and Clip Sport though keep the internal memory and card memory in separate databases. These databases are each limited to 2,000 songs. An 8GB Clip Sport is only around $37 on Amazon, while a 4GB one is around $32.
An 8GB Clip Jam is only around $31 on Amazon.
If you want to get a discontinued Clip+ or Clip Zip, prices on Ebay tend to be higher, especially for new ones.
