In reply to jon:
Yes the old Piola guides are out of print, thanks for clarifying that. Glad I've still got mine! Also, I didn't know a volume 2 of Aiguilles rouges was due - great stuff.
To the OP: Personally I have built up a range of different guidebooks for different Alpine areas and types of climbing over the years. The amount of climbing available is so vast that no one guidebook does it all and different guides have their plus and minus points.
Based on what you say in your original question, thinking of keeping costs down initially and reading what others have said my initial suggestions would be as follows for the Chamonix area:
Vamos: Valley cragging
Piola: Aiguilles Rouges
Vamos: Easy Ascents in Mont Blanc Range ( great ideas for a first season )
Also take lots of photos for future reference
These would be a good starting point IMO
Go and look at different guidebooks / borrow them if you can. Persuade mates to buy them! See what inspires you!
If you decide alpine climbing in the Chamonix area is what you want more of then I would also go for the Damilano guides 'Snow, Ice and Mixed'. Great overview pictures, plenty of routes but obviously all snow, ice and mixed! The Laroche / Lelong guide The Mont Blanc Range has limited routes but great descriptions for your early forays into the area so would also be worthwhile. Bear in mind you can also photocopy route descriptions at the Office de Haute Montagne in Chamonix - within reason.
Having got a season or two under your belt and, if you are anything like me realising there are several lifetimes of routes you want to do, you can expand your collection based on your ambitions. Fancy high altitude rock routes, get the appropriate guides. Want a greater variety of routes to choose from, get the A.C. guides etc.
One other thought, somebody mentioned about the ease of carrying guide books in the mountains. Personally, I often don't so I don't see that as a factor when buying alpine guides. I scan any relevant pages, cut out the bits I want and laminate them. Sometimes I combine info from different guides. Then just take the relevant bits with me. Light, weather proof, easy to read and keep in accessible pocket etc. You can take cards for alternative routes if conditions or weather or bravery dictates. Have fun!!