The price of 100 low-lead is approaching $6US per gallon. A newer Cessna 172 (one that was made in this century) rents for $90 to $120 per hour, sans fuel. The going rate for flight instruction in my area is anywhere from $25 per hour to over $100 per hour. I used to estimate that the total cost of earning a private pilot certificate was between $7000 and $9000, but now the cost seems to be more in the neighborhood of $8000 to $11,000.
Now if you decide to step up to the plate, the price of earning a private pilot certificate and, say, an instrument rating is equal to the price of a new car. Afterward, how can you maintain your currency without breaking the bank? Here are some suggestions and feel free to comment with your own ideas, too.
Many FBOs offer a block rate which allows you to put a larger block of your money into an account. In exchange for carrying a balance at the FBO, they offer you a discount on aircraft rental. This works to your advantage if you fly at least a couple of times a month.
Consider becoming involved with Angel Flight or a similar charitable organization. You can put your piloting skills toward a good cause and your expenses for each flight may be tax-deductable, too. If that's not your speed, perhaps the Civil Air Patrol might be the ticket.
Find a flying buddy and split flying costs. You can take turns being PIC, you get an extra set of eyes, and even when you're not manipulating the controls you still can look, listen, and learn. It's a great way to keep your head in the game while sharing your flying experience with someone who probably shares your passion for aviation. This can be a great way for instrument-rated pilots to maintain proficiency while splitting flying costs and duties.
Many pilots who have the work space, the skills and the interest take on the project of building their own aircraft. The experimental aircraft market is not for everyone, but it is a way to reduce the cost of acquiring an aircraft while keeping maintenance costs down.
The light sport pilot and aircraft initiatives have touted lower costs, both for the aircraft themselves and for pilot training. I'm still undecided on what to think of the light sport aircraft and the training of sport pilots, but some pilots have told me it's helped them keep flying affordable.
One way, and I'm not kidding here, is to buy your own aircraft. If you purchase an aircraft, by yourself or with a few partners, you may very well be able to reduce your hourly flying costs. Of course you and your partners will be saddled with all the responsibilities of aircraft ownership, but your overall costs may be lower than renting. And you'll learn a ton about aircraft maintenance in the process.
If owning an aircraft seems too expensive, there are organizations out where you really are in a club that shares ownership of one or more aircraft. The cost of entry varies with some clubs only charging a modest initiation fee while others charge hundreds (or thousands) of dollars to scare off less serious pilots. One advantage of a flying club is that since all members own a part of the aircraft, the aircraft is probably exempt from the 100 hour inspection requirement. This is a two-edged sword: The 100 hour inspection exemption can reduce hourly maintenance costs, but it may also provide an opportunity for cost-cutting and sloppily maintained aircraft. If this sort of arrangement interests you, one litmus test is to ask to see the aircraft logbooks. If the club balks, you should walk. If they allow you to look over the logs, what you read can reveal a lot about how the aircraft are cared for.
The cost of fuel has been rising at an alarming rate. While many FBOs charge close to $6US or more, there are some good deals out there and several web sites that can help you locate the good prices. Find the reasonable deals that are reasonably close and give those FBOs your business. You'll save some money and, perhaps, send a message to the larger airports. Unlike automobiles, it often makes sense and takes little extra time to fly somewhere else and buy fuel.
The bottom line is that flying takes money and if you love it, you can find a way to keep at it.