1. Wedding Band Equipment

Why it's hidden: Wedding band cost already typically includes fees for the musicians' time and the minimum amount of equipment needed. If your reception space is extra-large, additional speakers and microphones could be required to project the best sound quality.

The cost: Anywhere from several hundred to several thousand dollars.

How to avoid it: Before booking your wedding band or DJ, you need to clearly explain the layout of the space (or have them check it out, if they can) so the pros know exactly what they're working with. If they want to add in extra equipment, have them explain why it's necessary before signing a contract or agreeing to pay for anything else.

2. Postage Stamps

Why it's hidden: Stationers don't advertise shipping costs; if they did, you might decide to go with simpler (read: cheaper) invites.

The cost: Oversize, awkwardly shaped and bulky invitations will most often run you as much as $2 each to mail.

How to avoid it: Skip the fancy boxed invitations and multilayer cards, which can bulk up quickly and cost a lot more than you bargained for.

3. Wedding Dress Alterations and Steaming

Why it's hidden: Most stores don't include alterations (or steaming) in the price of the wedding dress, and they're not doing it for free – it can take up to three hours just to alter the bustier!

The cost: A simple hem can be less than $100, but completely rebuilding a bodice can send the price upward of $500.

How to avoid it: Ask about what the store charges for every alteration you may need before purchasing the gown.

4. Overtime Costs

Why it's hidden: Your band, DJ, wedding photographer and videographer are booked for just a certain amount of time, so if your wedding runs a little longer than you expected, they'll charge per hour.

The cost: Starting at $250 per hour.

How to avoid it: Factor in additional time for getting dressed and taking photos; that way, you can book your pros for a more realistic time frame. Get overtime costs in writing (they shouldn't be more than 50 percent more per hour than the regular rate), so you'll know what to expect if you decide to keep the party going.

5. Welcome Bag Delivery

Why it's hidden: Most hotels don't factor in a welcome bag delivery fee when you block rooms. And they may fail to mention the rate unless you ask – they'll just add it to your final bill. Inquire within; they may even charge you a fee for holding the welcome bags if you drop them off before the guests arrive.

The cost: Up to $7 per bag.

How to avoid it: During the booking process, ask about the hotel's policy on receiving and delivering welcome bags to guests' rooms. It may be free or cheaper if they hand the bags out at the counter as guests check in. If you don't want the extra charge, you can distribute them at the rehearsal dinner.

6. Rental Transport

Why it's hidden: You'd assume the rental companies would include these extra fees in the per-item costs (do they honestly think you're going to fit 150 chiavari chars in your car?), but surprisingly they don't.

The cost: From $50 up to more than $500.

How to avoid it: Ask the rental company what their shipping and packaging fees are up front – if the cost is too high for your budget, shop around a bit. You just might find that you'll actually save some money by renting items from a more expensive company that includes delivery costs at no extra charge.

7. Taxes and Gratuities

Why it's hidden: Even though these aren't exactly hidden – we all know there are taxes on almost everything – most couples don't think about how much they'll end up owing during the planning process.

The cost: This will depend on the total amount of money you're spending as well as the location of the event (taxes vary by state).

How to avoid it: There's no getting around paying taxes, but paying the entire bill in one lump sum can help lower the overall price. A safe bet: Tack on an extra third of your total costs to your budget for tips and taxes.

8. Cake-Cutting and Corkage Fees

Why it's hidden: If you use the cake or liquor provided by your reception site, the charge is typically wrapped into the cost. Going with an outside baker or your own wine can raise the price. Why? Because your venue's workers are responsible for slicing and serving each piece, then cleaning the dishes -- and this means more work for their staff.

The cost: From $2 to $5 per guest for the cake; from $1.50 to $3 for every bottle the staff opens.

How to avoid it: Be up front. Ask about cake-cutting and corkage fees before you decide to go with an outside source for either.

9. Cleanup and Breakdown Costs

Why it's hidden: Many couples spend so much time planning the actual day that they forget to budget for what happens when it's all over.

The cost: While a full-service venue won't charge for these things, if you're paying a flat fee to rent only the space, anticipate additional charges for garbage removal (up to $250) and cleaning (up to $500). And even most full-service venues require same-day setup and cleanup. So if you're getting married on a weekend, expect to pay time and a half for labor, and if your party goes into the wee hours of the morning, you may face extra charges for late-night pickup and cleanup.

How to avoid it: Read your contract carefully – the setup and breakdown costs should be included in the labor charge.

10.Non-Approved Professionals

Why it's hidden: Some venues require you to use caterers or florists from their preferred pros list – and tack on a fee if you don't.

The cost: Usually an extra 20 percent or more.

How to avoid it: Stick to the list, or choose a venue without one.