PIRATE NIGHT... WHAT a blast. That was the most fun we have had in many years. As far as costumes go, don't spend alot of money, unless you want to order a special costume. I couldn't see spending $100 online on a costume that might not fit right or look cheap. Besides, I had 10 people to dress so I didn't have that much money to spend. So I went to the local thrift store, searched around and found great pirate looking stuff.
I found my husband's striped pants for $1.50 and I bought a red t-shirt for him to wear, but we found a cool pirate t-shirt when we were in Puerto Vallarta for $10 and he liked it better.
I got most of our accessories: ear-rings, eye patches,

bandanas, tattoos, moustaches, and necklaces from
www.orientaltrading.com VERY inexpensive, but you have to buy more than one.. they come in bunches... like 48 eye patches for $2 or 12 pirate bandanas for $4.95 ... you can always "share" with your fellow cruisers.
I went to Party City and found Hooks and inflatable parrots to hook on your arm or on your shoulder if you are child sized. The parrots are a crack up, although on Pirate Night, we actually forgot to wear them!
If you stick to the basic colors... black, white, red, and stripes you will be fine. remember to have fun and say Arrrrrrrrrr alot, you will have a blast.
Our pirate pictures are linked here... you have to register to see them, click on
http://www.snapfish.com/share/p=100191118352928560/l=50449724/otsc=SYE/otsi=SALB