Amazon Warehouse
sold and shipped by Amazon

$34.96

ARRIS Surfboard SBV2402 DOCSIS 3.0 Cable Modem | Certified for Xfinity Internet & Voice (Black) for Plans up to 800 Mbps

https://www.amazon.com/ARRIS-Surfboard-Internet-Certified-SBV2402/dp/B07M9J3YZM/ref=sr_1_14?keywords=xfinity+modem&m=A2L77EE7U53NWQ&qid=1644731712&s=warehouse-deals&sprefix=xfinity+mode%2Cwarehouse-deals%2C56&sr=8-14

that would be paid off in about 2 months of rental
probably worth a shot

NETGEAR AC1600 Dual Band Gigabit WiFi Router (R6260)
Sold by Amazon Warehouse
Fulfilled by Amazon

$15.78

https://www.amazon.com/NETGEAR-AC1600-Gigabit-Router-R6260/dp/B01N9KQ07X/ref=sr_1_2?crid=25PIB4GBUC03O&keywords=wifi%2Brouter&m=A2L77EE7U53NWQ&qid=1644733104&s=warehouse-deals&sprefix=wifi%2Brouter%2Cwarehouse-deals%2C57&sr=8-2&th=1

more than I would need and decent reviews