The average price of a hotel room has outpaced inflation over the past several years. That fact, combined with stagnant salaries and higher fuel costs, makes it harder than ever to afford a vacation.

You may not be able to do much about the price at the pump or the cost of an airline ticket, but at least lodging expenses are somewhat flexible. Here are five different strategies you can use to save a significant amount when booking a hotel.

1. Using promotional deals

If you go directly to a hotel's website to book your room, chances are you will pay the standard daily rate or close to it. But if you're willing to do some research, elsewhere you may be able to find promotional deals which give a discount of up to 50% or higher.

Group buying and third-party websites are usually the best places to look. If you look at PointCom's deals section, you will see a number of hotel packages. For example at the time of writing, $299 could buy you one night plus spa treatments for two at the Casa Madrona in Sausalito, CA. If you went to that hotel's website directly, the will see the room alone will cost you that much.

2. Booking last minute

Now this strategy is a bit risky, because of course, the hotel might not have any vacancy left. But generally, if you try and book a room last minute, there's a good chance you will be successful as long as it's not a holiday and there are no local events going on at the time.

The theory behind the last-minute strategy is that a hotel would rather get something for a room, rather than nothing by letting it sit vacant. For this reason, you may be able to negotiate a better rate. In order to do so, you should call and speak to the local manager at the property (don't call the national reservation's line). The manager will start out with the listed price but if you explain that you can only afford a lower rate, often times they'll work with you.

3. Credit card discounts

Many of the mid to high-end credit cards on the market offer special hotel benefits and discounts. For example, on CreditCardForum they talk about the American Express Platinum Card, which gives an average of $450 in free perks at over 700 partner hotels. The credit card from Starwood offers help in reaching "Elite Status" faster, which will mean you can get late checkouts, upgrades and more at no additional cost.

If these discounts aren't good enough for you, then you could go a step further and even score free rooms. This is possible with many of the hotel-branded credit cards, since they often give a couple bonus nights when you apply. The Marriott Rewards Premier Visa gives up to 7 free nights and the Starwood credit card gives up to 6 free nights. Using one of these bonuses can be a quick way to save money.

4. Using memberships and group rates

Are you a senior citizen? Do you have an AAA membership? Are you in the military? These, and many other groups of people, may qualify you for a reduced rate at some hotel chains.

For example in California, AAA members can get 10% off at Best Western and Hyatt. Other chains like Marriott, Hilton, Hampton, and Starwood all offer at least a 5% discount. Considering that the cost for an AAA membership is around $50 per year, these discounts alone could easily offset that if you were staying someplace for a few days.

Something to be aware of though is that hotels aren't eager to give you these discounts. You have to ask for them. So before you book, do some research and find out which discounts a given chain has available.

5. Go during off-season

The difference in pricing between in-season and off-season can be several fold. If at all possible, try and plan your trip when others are not. Not only will you pay a lower rate for your room, but off-season will also mean less crowds.

So what exactly is considered to be "in-season" when traveling? Spring break, Christmas, and other major holidays almost always fall under this category. Weather will play a big part too, since people obviously want to go when the weather at the destination is best.

If you go during the less popular times, the savings can be substantial. For example, the most popular time for the Caribbean is during the depths of winter. But if you go from mid-April to mid-December, the lodging is usually around 30% cheaper. Not to mention, you will have more leverage during this time to possibly negotiate an even lower rate.

Image credit: espensorvik on Flickr