Yay! A new rat convert! Egggselent!
I know /exactly/ what you mean about the rat fever you're going through. It's terribly exciting getting your first rat and I only got my first in the last three years.
In my case, I fell in love when I saw a friend keeping a neurotic biting rat boy who they had in re-purposed glass herp tank. I was terrified of being bitten, so I decided, like you, to do tons of research to lower my chances of being bitten. I had no clue that they were keeping their poor rat in less than humane conditions; isolated with no rat companion, unhandled, in a glass unventilated tank, and on a commercial seed mix diet.
I am with Vlad in that no, I don't think you /shouldn't/ get a rat, but do continue to think through every angle. Rats are far and away the most expensive pet you can keep for their size in terms of money and time. You said time and money was an issue with you at the moment, so we wanted to help you think it through some more. Because their cage needs are much larger, their stimulation needs are much larger, and their health by and large pretty much stinks.
For a pair of same gender rats -yes you'll want to keep a minimum of two to address their extreme socialization needs-, for new rat start up cost and humane care over a 2 year expected life span, you will spend a minimum of $450 if they're healthy and you find ways to be frugal, and as much as $2250 if they're unhealthy and you don't luck out with finding cheap deals on care. I actually worked it out item by item. I've got it written up if you're interested, and can post it here.
I'm a testament for those two ranges. You can't anticipate what rat will be healthy and what rat won't. Especially if they come from a pet store. Even quality bred rats can be a work in progress. I have one rat I've spent $200 dollars on him over his life. He has never been sick or popped up a tumor once. And another rat who needed around $700 dollars before he finally succumbed at a young age to myco (extremely common lung disease in rats-every rat in the US carries myco, but some rats have genetically stronger immune systems and are able to fight it off for their life span).
I know we're throwing a lot of cautionary stuff at you but I've been a college student, so I know what it's like money wise and pet wise. I especially know how hard it is to avoid purchasing a pet you really, really want, even if it's in the animal's and your best interest. Heh- I bought a potbelly pig in college who, while I could pretty much afford him with my waitress job as long as he stayed healthy, had to give him away to a farm due to unexpected livestock zoning laws. So yeah, I had done a lot of research, but...
Many apartments and dorms have a strict no pet policy, and some even have a specific no RAT policy, because they are viewed as vermin. I've known several college students on the rat forums who had to rehome their rats in a panic because they had to move and the new place doesn't accept rats.
So yeah, we want you to have the best experience possible and not have to deal with the heartbreak of not anticipating what's needed and having to either rehome them or watch them succumb because you can't afford something they need.
That said...about your original question. Vlad is totally right, the cheapest and easiest way to get all of a rat's dietary needs met and have a stronger, healther rat than it might have been otherwise, is to purchase a quality lab block, and pair it up with a variety of veggies that you can pick up from your grocery store.
Quality lab block isn't often widely available at pet stores, but you can purchase it online easily enough.
The best nutritionally complete lab blocks available in the US are:
Harlan Tekklad--sold only to science labs, but can be purchased in smaller quantities through online rat rescue stores.
Mainly Rat Rescue Food Store: http://www.mainelyratrescue.org/store2/
It's available in different formulas, each geared to the nutritional needs of the different ages of your rats:
HT 2014--lower protein for overweight adult rats, or senior rats.
HT 2016--higher protein for adult healthy weight rats
HT 2018--very high protein for growing rats up to 7 months of age.
HT 8604--special formula for nursing mothers and baby rats up to 4 months of age.
Native Earth--This is Harlan Tekklad 2018 under a different name, and commercially available to the public. Petsmart/Petco carries this in some towns. You can also buy it in a 40 lb bags on Amazon. You can freeze whatever you won't use in 3 months, it won't lose nutritional value even buying bulk.
Three other brands you can get, but I know little about are:
What I feed my rats?
It all comes from this site: http://www.pxrats.com/ratfood2.html
Daily diet. One serving is the size of one lab block be it fruit or veggie:
Daily Menu Suggestions
- Quality lab block 3-6 blocks per rat per day.
(choose 3 for each day, 3-6 servings each) This doesn't mean you have to buy everything on the list. My rats have never had a bok choy in their life. Just select a variety of what works for you.
Sweet potatoes (cooked!! raw can be toxic)
Corn (only feed once a week)
(choose 1 for each day)
Grape or raisin
Plum or prunes
Daily Protein or Legumes
(choose 1 for each day)
If you are feeding them a higher protein lab block, feed less of this
Liver (cooked, unseasoned)
Lean meats (cooked)
TVP (textured vegatable protien)
Things to Feed in Moderation-
plain popped popcorn
Vitakraft yogurt drops
chicken or beef bones (cooked or boiled)
Kaytee chew biscuits
dried cornNylabones for chewing
Foods high in nitrates:
beets, celery, eggplant, lettuce, cucumber,
radishes, spinach, collards and turnip greens
Things To Never Feed-
foods (in excess) that cause gas
Orange Peels/Orange Juice (for males) - Pieces of the orange "fruit" are okay after washing
raw dry beans/Peanuts (contain anti-nutrients that destroy Vit. A & digestion enzymes, causes red blood cell clumping
raw sweet potato
green bananas (inhibits digestion of starch)
green potato skin and eyes (contains a toxin)
raw bulk tofu
licorice (suspicions of neurological poisoning)
raw red cabbage (contains anti-nutrients that destroys thiamin)
raw artichokes (inhibits digestion of protein)