I didn’t see that anyone did the math on these yet as to best conversion rate of magic to elixirs. Based on the wiki:
Bench/Streetlight - 2,500,000 cost to purchase, 250,000 cost to convert. Gives 1,650 elixir. Cost per elixir: 1,681 magic
Character statues - 9,825,000 cost to purchase, 950,000 cost to convert. Gives 5,700 elixir. Cost per elixir: 1,890 magic
So if you are buying purely for elixir conversion best to stick with benches or streetlights.
One additional note: to get an attraction to enchantment 5 takes 1,860 relics, which cost 75 elixir each, for total cost of 139,500 elixir. You need to convert 85 benches to achieve this, which costs 233,750,000 magic. So even if you are sitting on 400,000,000 magic (which is about normal for long time players) this only converts to ALMOST two level 5 upgrades. Better than nothing but this is absolutely not efficient use of magic.