Another expensive MP3 player for Nokia 3650 is MP3Go -- Price: $45.00. I don't think you should use or try this media player on your Nokia smartphone though. I did a test and it's very slow in browsing for media files.
The key features of MP3Go are:
File Manager UI for browsing media files, common play controls (play, pause, stop, forward, previous), album or song information is displayed (that's another common feature in any MP3 player), and support for NullSoft Winamp media files (.m3u). The software vendor of MP3Go recommends installation to memory card, if MP3 files are located in MMC.
The trial version of MP3Go will only play one minute of any song that it finds or detects. Not recommended to use or try, but for curious users, you can download it from Handango.
Image credits: Screenshots taken by the author, Cubix MP3 Player screenshot from http://www.handango.com/catalog/ProductDetails.jsp?storeId=2218&deviceId=2436&platformId=20&productId=189154