Tungsten Wedding Ring

I am looking to purchase a ring for a wedding proposal and I thought this ring looks gorgeous and was just wondering how much will it cost? I understand it varies on the diamond but a range would be most helpful.

I got this really cute ring for my bday from my bestie.. hers says best and mine says friends. I love it but she didn’t know ring sizes so she bought a size 6.. and i have big fingers, and the ring cuts off my circulation. is there a way to make the ring bigger??
Oh yeah and I wear it on my ring finger but on the pinky it’s too big.