Yes you can run Crysis 1 on 2GB of ram, and the GTX 650 wouldn't really be a good recommendation nowadays since his CPU isn't that bad and should be pair nicely with better cards.
Second generation i3s aren't that bad as gaming chips, even if they are limited as dual cores.
As already mentioned, if possible go for an 8GB ram kit, and go for a 2GB GTX 650 Ti Boost or Radeon 7850.
http://www.newegg.com/Product/Product.aspx?Item=N82E16814125457&nm_mc=AFC-C8Junction&cm_mmc=AFC-C8Junction-_-na-_-na-_-na&cm_sp=&AID=10446076&PID=3938566&SID=
http://www.newegg.com/Product/Product.aspx?Item=N82E16814121728&nm_mc=AFC-C8Junction&cm_mmc=AFC-C8Junction-_-na-_-na-_-na&cm_sp=&AID=10446076&PID=3938566&SID=
http://www.newegg.com/Product/Product.aspx?Item=N82E16814127663&nm_mc=AFC-C8Junction&cm_mmc=AFC-C8Junction-_-na-_-na-_-na&cm_sp=&AID=10446076&PID=3938566&SID=
Crysis 3 is very CPU intensive, so you will be held back by that i3, but either of those cards should give you a decent experience with it.
Crysis 3 CPU scaling
http://static.techspot.com/articles-info/642/bench/CPU_03.png
Also what's your power supply? if you need a decent one for any of these cards then
http://pcpartpicker.com/part/evga-power-supply-100b10500kr
http://pcpartpicker.com/part/thermaltake-power-supply-sp550pcbus