The only thing that can scare you is agar-agar. No, it cannot be replaced with gelatin or pectin – completely different properties, functions and results. If you do not know in what store to buy it – search the Internet, there are a lot of sites, the prices are affordable. If you live in Khabarovsk, I will be glad to help you with its acquisition. All the same, home-made marshmallow is worth it, believe me. Those, who tried it, said: "This is exactly what a real dessert should be like" – a delicate, melting in the mouth, with a thin fragile crust and a pleasant aroma (banana or other).