1. Dress pants by Ann taylor; 2. Blazer by Anthropologie, Blouse found at Shopstyle.com
Depending on the type of job you are applying for you will have some flexibility in terms of clothes. You don't always need to have a suit with matching pants and jacket. What is important is that you look clean, neat, and well put together. Your shoes should always be polished and avoid chunky and noisy jewelry that distracts from what is important: YOU.
You can opt for a nice pair of dress pants and a blazer. The colors do not need to match, but should be complimentary to each other. Underneath the jacket wear a nice blouse. Avoid sheer fabrics unless you are wearing a tank top.
You don't really have to spend much money. Lose items like the above can be found at outlet stores like Marshalls, TJMaxx, and Ross. The other day I saw a really nice CK silk-like blouse for $19. Invest in items that are NOT trendy, but are versatile. You can wear navy pants multiple times with different shoes and different blazers. Stick with neutral colors like nude, navy, gray, and black. You can always add colors by adding a pashmina or other accessories.
Most important do not wear high heels if you usually don't wear these types of shoes. You want to be comfortable and focus on your qualities as a candidate, not your sore feet!! One of the complains I have about women shoes and fashion is that there is a tendency to glorify and advertise high heels shoes, rather than fashionable flat shoes. I will rather see how an outfit looks with flat shoes than high heels. When I lived in London I saw many business women wearing ballet shoes. I opted for ankle boots with a short heel. You can always wear tennis shoes until you get to the office. Then switch to something a little bit more business appropriate. But the rule is that you need to be fashionably comfortable.