Is the Magic Lamp cost effective in PS1
There are two issues I see here, inventory limits and whether you'd spend more money on flashes throughout the game if you had to use one every time.
You get many flashes for free every time you beat a Sphinx or Vampire. They cost 20 meseta. You'd need to buy 71 before it would become better to use the Magic Lamp as far as cost is concerned.
The other issue is inventory. I haven't really had that issue until endgame. You can always get the Magic Lamp in Baya Malay once you can open magic doors if need be.
I'm leaning toward the Magic Lamp not being worth it, but I haven't played through the game without one. Have you, and what do you think?