The standard definition of a city continues to change. cities continue to grow outward and in some instances, and expand large enough to be considered mega cities. These urban areas are defined as metropolitan areas where populations exceed 10 million inhabitants. Going off those numbers, New York City is 9th largest city in the world, as it has a population of 21 million. Los Angeles ranks as the 18th largest city in the world with a population totaling 15 million, according to City Metric.

Cities are attractive for a variety of reasons, such as the urban lifestyle. In a six-point manifesto, a London-based alternative think group, The School of Life, released a guideline on how to make a city attractive. As highlighted by The Guardian, among their suggestions were visible life; the idea that cities are beautiful if people are constantly seen out and about. Other points center around a city's location, and the belief residents should embrace their local roots to make their living area stand out. The ability for city residents to get lost in the city's offerings without actually losing their sense of direction also makes cities attractive.

However, potential homebuyers can flock to other areas outside of these megacities to experience the urban lifestyle just as much. Time Money recently highlighted some of the best big cities. These areas are either well-known or up and coming. Before moving to one of these areas though, you have to make sure you can actually afford a house.

Down payment comes first

Silicon Valley is where technology giants and startups research and release the latest gadget or innovation from the future. The downside to this tech surge has been skyrocketing prices in the surrounding areas, such as San Francisco. Residents in this city may have difficulty saving for a down payments, even though they may have a steady income.

According to Trulia writer Paula Pant, homebuyers should ideally have a 20 percent down payment, otherwise banks will add on private mortgage insurance. Rates can range from 0.05 percent to 1 percent of the total loan amount. If you're set on moving to an area with a good technology environment, look no further than Pittsburgh. Google, Apple and Uber are some of the big names to have set up research centers in the Northeast city.

The market is attractive for homebuyers because the median home price is $115,000. The price is well below the San Francisco median home price of $738,000, as highlighted by the National Association of Realtors.

"Between academia, innovative companies, and lots of startup activity, [the tech world] loves it here," Kamal Nigam, engineering manager at Google's Pittsburgh office, told Time Money in an interview.

Account for monthly expenses

Once you purchase a house, your largest monthly expense will be the mortgage payment. After that, you should budget enough of your income for other obligations. For instance, you should have enough of a cushion to make monthly payments without stressing too much, and in the event taxes increase, you can still afford the mortgage. Trulia also advised homeowners to set aside 1 percent of their mortgage for home repairs and maintenance. This fund can help pay for home improvement projects that are relatively simple, or more expensive ones that might require a home inspection services company to look at changes to areas such as electrical wiring and plumbing.

After that, you should have money left over to use for personal enjoyment. If you're a young homeowner looking to live in a city but still enjoy nature, look no further than Denver. The city's median housing price is $288,000, which represents a 10.3 percent increase from 2014, according to the S&P/Case-Schiller home price index. Compared to other prices out west, Denver still represents a great for homebuyers. In some areas, living downtown may might be affordable, but in Denver, homeowners can buy a house only 10 minutes away from downtown.

Millennials in particular are attracted to the Rocky Mountains because of its youthful vibe and strong emphasis on health. The city currently has approximately 110 miles of bike lanes and one of the nation's oldest bike-sharing programs.

You're in for the long haul

The make-or-break point whether to buy or rent will vary depending on location. In an interview with ABC News, Zillow CEO Spencer Rascoff​, said if you're going to live in a property for at least two years, you're better off buying instead of renting. You'll need to live in a house longer if you're in a more expensive location, such as Manhattan.

You may not find yourself open to the idea of staying in one location for too long. However, Omaha, Nebraska, is an up-and-coming city that could sway some homebuyers' minds. The population is 443,000, and the median home price is 116,300, according to Time Money. The publication also said the average commute time is 18 minutes. In a large traffic-congested city such as Los Angeles, 18-minute commutes are unheard of.

Other than low home prices, Omaha is seen as an attractive city because it combines big city living with a small-town focus. The city is heavily praised for its food scene, and its emphasis on incorporating local produce. Homeowners comfortable with staying in one location can appreciate Omaha's offerings, and see what's in store for the city in the future.

Purchasing a home requires due diligence and plenty of research. If you want to live or move to a big city, you don't necessarily have to go to popular options. Cities such as Denver and Pittsburgh offer low housing and plenty of opportunities. Homebuyers just need to make sure they have enough for a down payment and budget properly.