Other than free Starhub issued Nokia XS-2426X-A XGS-PON ONR (with wireless AX6000) and Singtel issued ZTE F8648P ONR (wired only, no wireless), other 10G capable routers are not that cheap to get.
Cheapest is proble Starhub issued EB810v and Singtel issued HB810 as well as MR issued Archer BE805. All three are 10G capable triband WiFi 7 router (with 6GHz band and 320MHz channel bandwidth). But then EB810v and HB810 are kind of locked to Starhub and Singtel for firmware updates as they are both service provider models. Only MR issued Archer BE805 is not locked to MR.
Other 10G capable routers: most of them will be more expensive than going with the following two options.
a) 5Gbps plan: S$55.39 per month 5Gbps with TP-Link EB810v (using XGS-PON ONT)
b) 10Gbps plan: S$59.99 per month plus one time S$50 top-up for the TP-Link Archer BE805 (using XGS-PON ONT)
1) Asus RT-AX89X dual band WiFi 6 AX6000, no 6GHz band
2) Asus ROG GT-BE98 (S$1099) or ZenWiFi BQ16 WiFi 7 (S$898), quad band WiFi 7
3) Ubiquiti UDM Pro (S$599) or UDM SE (S$799), wired only, no wireless
4) Xiaomi BE10000 (RMB 1599) triband BE10000, no 6GHz band
5) Asus RT-BE88U dual band BE7200, no 6GHz band
6) TP-Link Archer BE800 triband BE19000 or Deco BE85 triband BE22000
7) Netgear Nighthawk RS700S or Orbi 970 (super expensive)
8) Mini PC based -- Intel N100/N305, Atom C3758R based, or higher end Intel 12th/13th gen CPU based, with dual or quad SFP+ ports
...