I was lucky and did purchase the Olimex GD32F103RBT6 Maple board from Amazon for $9.00
including delivery and taxes.
Here is the link https://www.amazon.com/gp/product/B01APN27ES/ref=od_aui_detailpages00?ie=UTF8&psc=1
Now I feel unlucky, because the board is not anymore available. The other reason to be slightly sad is that I failed in downloading from Arduino and was able to brick the board for USB access - lost the maple boot loader. Loading through serial or ST-link didn't work for me. The only way at the moment to use the board is to use EmBitz 1.00 with ST-link. Works without any issues.
The challenge was the tiny 10 pin connector with 0.05 pitch used for ST-link SWD. The required flat cables and connectors are not widely available. I had to sacrifice one of the flat cables used in my LPC-Link 2 development boards. I was too lazy to review the LPC-Link 2 documentation to see if it was a perfect match with the Olimex SWD connector. It could have been possible that without cutting any cables, I could connect the LPC-Link 2 to PC with USB for ST-link and then connect the LPC-Link 2 to Olimex Maple.
I will update the STM32F103_Med64.csv table in F103 github with the pin numbers used in the Olimex boards, including the Arduino pins, UEXT pins, and Extension pins. I will add this board in the F103 github Wiki at https://github.com/OliviliK/STM32F103/wiki