The difference is that GBA not only had TV shows (which can be played through Game Boy Advance Video cartridges), but could also play video games, as it was built for that. Thus many retail stores were left with a surplus of the device. Original retail price was about US$70.
GBA featured not only TV shows but also allowed playing video games using Game Boy Advance Video cartridges. This dual functionality caused a surplus in retail stores. The initial retail cost was approximately US$70.