Me interesa comprar esto
Estoy interesado
Sure, I'd be interested in buying your bicycle.
El total/la suma
Seem interested, I suppose. Ask what they're going to be buying?
Gracias por comprar el vestido
comprar asistente ardía plena
Te estoy comprando zapatillas de tenis
Yo solía estar interesado en la pesca
Are you selling or buying? I am interested in buying.
You say, "What type/kind of books interest you?" And you say it, "Qué tipo/clase de libros te interesa?"
Me interesan mucho la ciencia y la biología.
Are you interested in buying a broken bike?