Optifine cape?

I’m thinking about buying Optifine cape, other that already bought it, was it worth it? Does it work on all servers?

Also I’m wondering about the payment because when I hit paymentwall and then type my address it justsays: “Unfortunately, this method of payment is not available in your country”.

So what does that mean? Which payment methods are available? I already tried different browser and disabling antivirus.