I have listed aircraft stamps for sale on my aviation stamps blog:

http://aviationstamps.blogspot.sg/

My prices are very reasonable and much lower than those quoted by sellers on ebay.  Have a look.

Here are a few of the items listed:

Cameroon.   1976.Concorde's First Commercial Flight, Paris to Rio de Janeiro.  SG MS769.

Cat. £.7.75.  MNH. Price: US.$4

Cuba  2006 Aircraft.  SG 1961-67.  MNH

Cat. £7.70  MNH.  Price: US.$3.50

Djibouti Republic. 1978 Air. Djibouti Aero Club.  

SG 721-723. Cat. £3.75. FU Price: US.$1.75

Dominica. F1 fighter souvenir sheet. 

SG SG MS251a. Cat. £.4.25. MNH.  Price: US.$2.

French Southern & Antarctic Territories. 

 1969  1st Flight of Concorde.  SG 53. 

Cat. £60. MVLH  Price: US.$20.

Gabon.  1983 Air. Ballooning Anniversaries. 

SG 857-59. Cat. £4.05.  MNH. Price US$2.

Gabon.  1967  Famous Aircraft.  SG 88-90.   

 Cat. £25.  MNH.  Price US$12.

Samoa. 1998 80th Anniv of the Royal Air Force.  

SG 1029-1032  Cat. £5.90  MNH.  Price US$3.

Wallis & Futuna Islands. 

1976. 1st Commercial Flight of Concorde.  

SG 253.  Cat. £48. MVLH  Price US$18.