i have just searched ebay and found 2 head unitis for sale 1 is £180 but needs 2 knobs off the front but you will have these anyway and the other for £120,
this is just incase lexus decide your head unit has had it ,you have other options open to you.
http://www.ebay.co.uk/itm/GENUINE-LEXUS-CT200-CT200h-CD-PLAYER-RADIO-UNIT-86120-76220-BREAKING-PARTS-/291882655021?hash=item43f58fdd2d:g:LocAAOSwjXRXansQ
http://www.ebay.co.uk/itm/2011-14-LEXUS-CT200H-CT200-STEREO-HEAD-UNIT-CD-PLAYER-RADIO-BREAKING-/331992227808?hash=item4d4c475fe0:g:bLwAAOSw-CpX9ohj