Tying the knot

You asked. She answered. Congratulations! Now open your wallet. The average U.S. wedding costs $27,000, according to the Knot, a wedding planning website.

The diamond industry suggests spending two months' salary on an engagement ring. If you earn $40,000 a year, that means spending almost $7,000 on the ring. Financing it? Allow for interest, too. That's love.

Wedding costs are utterly individual, of course. You might not do an engagement ring at all and opt for plain metal wedding bands versus stones. Maybe her parents have saved for a big wedding. Maybe you'll elope. Don't count on any of this.

Other potential budget dings: an engagement notice in a local paper, a plane ticket so Grandma can attend the wedding, rose petals to throw instead of rice, an extra (i.e., more manly) cake for the groom.

Also, check "8 unexpected wedding costs" for things you might never have dreamed of, like Spanx. At least if you elope you might be able to skip the foundation garments.

Total: one-time expenses of $34,000.

Expensively ever after?

With the wedding included, that puts the cost of five years of singlehood at just under $150,000. And you still won't be done spending money.

Plenty of newlyweds think homeownership is the next logical step. They shop for square footage before the ink on their thank-you notes has dried. (By the way, you can hire a service such as WeddingThankYouWriter.com to write and mail those notes for about $4 a pop. Don't tell your mother-in-law.)

The good news is that both interest rates and home prices are dropping. The current median mortgage payment is about $700. But keep your real-estate dreams in step with your financial reality by using MSN Money's homebuying calculator.

Whether buying or renting, you may be able to furnish the new digs by merging your worldly goods. But if your beer signs and her Ikea décor clash too painfully, you might decide to start over. Expect to spend thousands unless you shop at "curb mart" or on the Freecycle Network or Craigslist.

If that rental or home purchase is far from one or both jobs and public transit doesn't cut it, it may be time to buy one or two vehicles. The average price of a new car in the U.S. is $28,400 -- and remember, it costs more to insure a new auto.