Rather than spending money to buy a Windows 10 license, the alternate way is to buy an original Windows 7 license and upgrade it to Windows 10 for free.
Currently, a Windows 10 retail license costs S$229. You can now purchase the Windows 7 original license at a fraction of that costs at S$54 at this link (Qoo10 store). While stocks last.
US and international readers get also get hold of Windows 7 at a discounted price at Amazon for USD 57.