Does it cost money to send SCI?

If you want money, the operating cost of SCI is also relatively high, so you also charge a page fee, some don't, but most of them do. Moreover, the edition fee of SCI is not cheap, ranging from several hundred euros to several thousand dollars, that is, tens of thousands of RMB. But the key is not money, but the difficulty of publishing. So, what you have to care about is whether it can be published smoothly. If you are interested in publishing SCI papers, you'd better be familiar with the papers in several SCI journals first. If you think you can get in touch with them, you should write and submit them carefully, but rejection is most of the time, so you should be mentally prepared. In addition, there are some institutions that provide auxiliary publishing services for SCI papers, which you can also learn about, such as paper net, Tao Tao. But on the whole, I suggest you try to contribute yourself first.