This should absolutely demolish the c5.12xlarge, especially if you need any disk IO or bandwidth.
Or from a different provider, a Dual Epyc 7281 (32 cores) with 256GB (and ssds, hdds and bandwith included) for $400/m.
You can get cheaper if you're willing to host in Europe. And this is dedicated, so no additional power or storage or maintenance cost. Stuff breaks, they replace it. Also, your commitment is 1 month.