Budget the price of the car and figure out the scheduled maintenance costs over the time and mileage you plan to own it. Then add in what an unforseen repair will cost you (clutch or any know issues with the year car you are looking at) as well as insurance. If that number doesn't scare you and fits realistically within your budget then go for it.

Make sure you budget for real life. I know people who figure a budget and then think "I can get by on $150/month for food." just so they can convince themselves that they can afford the purchase they want. Keep every receipt for every dime you spend for the next month including stops at the coffee shops and newspapers right through the big stuff like current car payment, insurance, home heating, electric, etc. Use that as your budget to base it on. If you can swing it, go for it. If not, maybe look into something a little less pricey or less expensive to maintain.

Personally I have lusted for a Lambo since I saw my first one at 5 years old in 1978. I have wanted a 911 for about the same amount of time. I am 34 years old and currently don't own either as the budget says no. But I am keeping my eyes open for the right car at the right price and that is when I will make my move.