For the following post I'm going by this guide to budget and expensive:
Budget:
$100 or less
Expensive:
$100 or more
The thing about the budget price point is that you are going to get pretty good performance and features. The Cooler Master HAF 922 has very good cooling for example. The Lian Li PC-k62 has some of greatest features of any case on the market and retains great quality. So as you can see, a budget case is not a bad thing.
However, I have a general rule; you should only have to buy one case, or at least one that will last you many years and upgrades. A case is more than a box with fans, it is an object in your household that conveys a message to others and to yourself. While I feel there is nothing wrong with flashy lights accents, there is a limit as well.
A case should also have the features you need. If you are watercooling, then don't buy an Antec 900 and expect to be able to bolt in some radiators, it won't happen. If you keep your case on at night in your bedroom then LED fans with high RPMs aren't for you. If you carry your case to LAN parties a lot then a large steel full tower isn't going to be fun to carry around. These are just some examples.
Lastly, a case is important because you are CREATING the PC inside it. You pick out the case, and the parts there in. It is your creation and you should customize it and personalize it the way you see fit. A case should reflect you and it should be something your proud of, because it takes a lot of knowledge and time to pick out the right parts while putting them together responsibly and keep that computer running efficiently and correctly. The case is the most noticeable part of your construction.
This is where the debate becomes difficult between a budget case and a higher end case. The thing is I don't think you should ignore the budget sector, nor should you rule out the higher end segment if you can, find the case you want and get the damn thing. I bought my first Silverstone TJ07 when I was 15-16 years old with 2 minimum wage jobs a car payment and high school. It wasn't easy to come up with the $320 + shipping that I paid, but I scraped it together (I don't recommend doing this however
)
This is your hobby, enjoy it or find a cheaper one, though it isn't that expensive of a hobby if you are smart about it.