This is my Netgear AC1900 WI Fi Cable Modem Router, model number C6900.
It is approximately three years old, but still has modern day performance.
It supports Wi-fi videos simultaneously on multiple devices in our house (cellphones, computers, smart TV) with no buffering.
The Wi-fi is both 2.4 and 5 gigahertz, and it also has 4 ethernet connections (see picture), which means you can connect multiple devices directly such as computers, printers, etc.
It will definitely perform well with other technology for at least three to five years.
I believe I paid approximately $150 when new, so $30 seems fair.