I’d suggest a 10Gbps switch as well. 2.5Gbps seems to be quirky at times are the reports I hear from people.
Super cheap on Ebay - Avaya, Extreme Networks, Aruba, any of the commercial brands.
A 10Gbps Switch with 3 ports or more is a bit more than this retiree can afford. They do look like they are coming down. I've not seen 10 Gbps ports on any cheap mini's yet. Using 2 10Gbps Dongles in the place of the two 2.5Gbps ports, increases the minimum price from about 7 dollars for the CAT6. to about $240 (Two 10 GBps dongles and CAT 6 2 meter Cable) for most.