I would love a 500mm f/1.4 too...
Hey, is that the new model that comes with a free Jeep to be used as a tripod with that lens?
Seriously... there are 2 issues here for the OP.
1. Lack of knowledge. They do not know what they want, that is the first thing that needs addressing. Be CLEAR on your needs and desires. Once that is sorted out you will find a direction. Lack of knowledge about what is out there. Google is your friend. Find out why a specific camera would be good or bad for you. That takes research... lots of it. I would say that before I made the decision to purchase my D700, I read a good 200 hours on the net about it, downloaded the manual from Nikon, emailed, PMed about 20 D700 owners and spoke to a good 10 D700 owners either face to face or over the phone... often long distance.
2. Lack of funds. Well, there is no fixed solution here but plenty of possible directions. I'll touch on those below.
- Keep the same camera, invest in high end lenses. This is usually the smart thing to do, ONLY if you invest in quality glass. Good glass today will be good glass 25 years later. Crap lenses are crap today and for forever. The same cannot be said of cameras as they improve from generation to generation.
- Accept a lower end upgrade camera that offers minimal increases (XSi over the XT for example) and know that in the near future, you will be spending yet again on a camera upgrade that offers you again, small increases.
- The "where there is a will, there is a way" method. This is where you are clear on what you want and will do what is needed to get it. For example, if you were clear you wanted a 5D II, you worked your hiney off, saved for it and got it. Not only does this method build a little character in the younger aged group, it puts a much higher quality camera in their bags. Be aware that as you go up the scale of camera quality, lens quality should be held to an equal scale. Don't be putting a kit lens on a nice camera and cripple it's potential.
The lack of funds situation... It is not exactly the same, but as an example, my niece moves from high school to college this year. She wants a new wardrobe for when school starts. Instead of going to mommy and daddy and filling their credit cards, all on her own, she has found a part time job in a store (by some strange coincidence it is the same store that she plans to shop for her cloths in, and as an employee gets significant discounts... lol), tutors 4 students in biology and trig and 2 students on piano on a weekly basis and does small chores for me which I pay her for (ok, ok, they are mostly totally useless, but I want to help her out and as I said, at least it shows character... lol)
That are a couple of the possibke options that I see. Hope that helps out.