According to an article on STV (link below) in the previous 5 years ICT paid £202,000 in transfer fees and received £881,000, a transfer profit of £679,000. Obviously the figures are questionable because clubs generally don't publicise fees.
They don't mention any names, but I've put in brackets the transfers I can think of that would have involved fees, although for some years it doesn't quite stack up with the figures in the article.
Fees paid
06/07 £80,000 (Rankin, Paatelainen)
07/08 £66,000 (Imrie)
08/09 £56,000 (Rooney)
09/10 £0
10/11 £0
Fees received
06/07 £44,000 (Brown, Proctor, but I reckon we got about £100,000 + £25,000 respectively for them)
07/08 £141,000 (Rankin)
08/09 £638,000 (Niculae, Cowie)
09/10 £58,000 (Imrie)
10/11 £0
If anyone can shed more light, feel free.
Source:
http://sport.stv.tv/football/scottish-premier/celtic/295669-what-has-your-team-spent-on-transfers-in-the-last-five-years/