Please don't be too discouraged by the bitterness and negative responses in this thread -- some people who hang out here
really don't like regional pricing, but this forum has historically been a bit more helpful and less hostile than it seems right now.
With regards to Alipay and other payment methods: I'm sure GOG will be willing to start accepting these as they expand into regions where PayPal, for example, is not used as much, but probably not before -- besides direct credit/debit card payments, they currently only support PayPal and paysafecard, as far as I know, and that's because those are two of the most popular methods for online payments across North America and (in the case of paysafecard) much of Europe. There would be little purpose to offering Alipay as a payment option before they are prepared to support both Chinese language and Chinese currency, and doing any of those would probably be an enormous undertaking for a company of GOG's size (not least because a Chinese-localized GOG store would probably have to have many more restrictions put in place to comply with government regulations).