The most affordable way to get a 16 port 10GBASE-T switch I know of is to go with the Netgear XS716E 16 port 10GBASE-T switch. Its MSRP is $1099 but usually is on amazon (as linked) for about $899.

Still not all that affordable but better than some of the options out there with having to get SFP+ transceivers.