For Brands available in Local market (New)
1) Hella costs around 2.5k - 3K
2) Bosch costs around 2.2K
3) Segar (Turkish Brand) costs around 650, But very very good PAAN PAAN sound.
From Used Parts mkt (like bilal gunj)
You can original horns like FIAAM, Bosch, Hella, for around 300. But be careful most of the horns are repaired there.