Petland Discounts (by me, anyway) had the tank for 80 bucks after tax. The stand was 76 from Walmart. The heater cost me 30 and I'm sure you can get it for less on-line. If you want a high quality filter, you can get an Eheim 2215 from jcaquatics.com for 87 before tax and shipping and it has all the media you need for a while. These go for about 150 in most stores and, from what I've read here, they seem t be looked at as "top of the line". You can get 2 24" All Glass Aquarium brand hoods for about 40 a pop. I believe that's cheaper than trying to get a full size hood for a 55. You'll need between 10 and 12 bags of gravel, a thermometer for like 5 bucks, test kits for pH, ammonia, nitrites and nitrates. I got 2 kits; one tests for ammonia, nitrites and pH. That was like 30. The other one was for nitrates and was 20. You'll also need tap water conditioner to remove chlorine. That's like 5 bucks.
So, you're looking at about 430 for a decent set up without gravel or decorations. Gravel runs about 5 bucks per bag so you can add another 50 bucks. You're probably going to spend around 500 before you even get to put fish in the tank.
Not to make it sound like it's some kind of elite privelage to own a larger tank (and 55 isn't all that big) but, you might want to consider going with a smaller size to start off. Maybe a 20-40 gallon? You can always upgrade later when you don't have to work your butt off for the sole purpose of owning a fish tank.
So, you're looking at about 430 for a decent set up without gravel or decorations. Gravel runs about 5 bucks per bag so you can add another 50 bucks. You're probably going to spend around 500 before you even get to put fish in the tank.
Not to make it sound like it's some kind of elite privelage to own a larger tank (and 55 isn't all that big) but, you might want to consider going with a smaller size to start off. Maybe a 20-40 gallon? You can always upgrade later when you don't have to work your butt off for the sole purpose of owning a fish tank.