BaiSiwa Right at the start, I don't think having the paid "Origin" Stone option will work. But down the line, when the picture is clearer of how original works perform, I believe having the option to buy paid origin stones to support is a way of not only voting up a work in the rankings, but also supporting them.
Granted the price of each origin stone will need to be dictated and webnovel will surely have a cut. But it is another chance to support other than patreon through webnovel I feel, since they do ask for your bank info anyway.
There will still be 1 free origin stone per day per user to use to vote up in the rankings for original works. I think that's a really good idea. For the paid origin stone in the future, I'm just thinking at the top of my head right now, 1 origin stone = 1 usd for example, limited to maximum of 5 origin stones bought per week or month in order to minimize abuse.
How much the author takes home from the paid origin stone is still up for discussion but I do believe the bigger pie needs to go to the author and webnovels cut is their facilitation fee.
Hope that helps clear the idea up. But the paid option is for later, not right now. It's more of a vocal support for your favored original work if you really want to support and vote them. At least the option is made available to you at a price and at a fixed quantity per week/month. =)