Hi, well on Praslin, if your looking for some entertainment that doesn't cost anything or alot (depends on what you consum) and to want to mingle with the locals, there is a shop (Morley's Shop) in Amitie, behind the Airport that has live music friday and saturday night. Any musician or singer can just come and play/sing. You can buy drinks from the shop and enjoy the music, or even dance. Usually a lot of people there, including myself.
If you ever want to join just let me know. This is something that probably not many expats or tourists know of. Like I said, mostly all locals who are looking to have a good time.