Just a few comments on some of what has been discussed here...

First, you can go pretty light and still keep costs down on at least some items. A few things that come to mind are

• Panniers - Nashbar or Performance waterproof ones are inexpensive and much lighter than most while still being durable enough.
• Stoves - Pop can stoves are essentially free and very light. The fuel is heavier per BTU, but that isn't so much of an issue for bike touring since you can carry less of it and restock frequently. A Pocket Rocket is light and pretty cheap.
• Pots and Pans - These can be very light without going high dollar especially if you limit yourself to one very thin gauge pot. We carried one pot for the three of us on the Trans America and managed some fairly elaborate meals.
• Tents - just going with a smaller tent can get the weight pretty low. For example the Eureka Solitaire can be found for $50. Higher end tents can be found on sale at close out prices if you watch for them.
• Sleeping Pads - Inexpensive foam pads work in a pinch and are light weight. That said this is an area where I splurged and bought a NeoAir which was obscenely expensive but is extremely light, packs tiny, and is very comfortable.
• Sleeping Bags - I managed to finish the TA with a $70 Slumberjack SuperGuide. It weighs a fairly light 2 pounds 9 ounces and Campmor now has it for $50. the rating is a bit optimistic, but with the addition of some clothes piled on top of my body inside the bag, I was comfortable down to 30 F or so. It isn't my first choice of bags and I have since replaced it with something more expensive, but it was OK.

Also you can go lighter just by skipping some items completely. If you look at some packing lists you can get by without more than half of the stuff on them.

Something was said about needing more for longer tours. I don't find that to be the case. I need the same stuff for a few days as I would for 3 months.

Oh and the comments about space in the tent... Just me, but I prefer to leave anything I don't need in the tent on the bike and in the panniers. On a rainy day I might sleep in late or read for a while, but get up and move on after a bit. I am more likely to try harder to camp somewhere that I am under a roof like a picnic pavilion or whatever and am also more likely to get up and go to a diner for breakfast if it is raining and there is one within an hour of riding or less.