Swap SABRE or DAYWORLD and get all four of these :)
 

1. SABRE by James Follet
Sabre 002, a synergetic, air-breathing rocket engine developed in France, will revolutionize air travel. Fearing the death of the US aircraft industry and the loss of hundreds or thousands of jobs, a union boss plans a disaster for Sabre's first fare-paying flight.

2. SPELLSINGER by Alan Dean Foster (Intact but unpostable for Wear)
It is a world where beasts walk and talk as men, armed with swords and daggers. Jonathan Meriweather finds himself plucked from peaceful university life and catapulted into this strange new world to become part of a very special fellowship. Soldier and crusader, he becomes the Spellsinger.

3. DAYWORLD by Philip Jose Farmer
The New Era, several thousand years in the future, seems a utopia. War, poverty, hunger and pollution are all obsolete. Overpopulation has been handled by dividing the population into seven groups, each fraction living one day a week while the others await in suspended animation. Farmer's Dayworld chronicled the life of a man whose unique abilities allowed him to assume a different identity for each day. As this sequel opens, he has been caught and is being questioned. Escaping from his Manhattan prison, he flees to the wilds of New Jersey, falling in with a rebel group hiding out in caves. Along with them, he journeys to Los Angeles and contacts a larger subversive organization bent on radical change.

4. NIGHT OF LIGHT by Philip Jose Farmer (Intact but unpostable for Wear)
Every seven years, the placid planet of Dante's Joy becomes a waking nightmare of death, deformity, and madness. To escape, the populace has the choice of Sleeping--lying drugged in their tomblike houses--or taking the Chance--staying awake and going abroad while their world goes berserk. They become what their innermost longings dictate, whether it be a beast locked in the vilest bowels of depravity, or a supreme being raised to the flowering serenity of truth and light. Thousands are mutilated, killed, transformed into monstrous things. John Carmody, a conscienceless exile from Earth, arrogantly chooses to take the Chance. Reeling, shrieking his fear and despair, Carmody confronts the Night of Light, the unknown and unknowable..

Take Care,

Lisa

I ordered Dayworld from you, if the offer is still up. Thank you!