My youngest two are going with the simple, warm costumes. Dd will be a monkey and ds will be a dog. I bought the dog costume used and the monkey costume is borrowed from a friend.
Ds1 is going as a train engineer. He has a fascination with trains that has yet to die and is so not into the scary aspect of Halloween. He already had a train engineer hat, gloves and vest so I just needed to buy him the shirt he thought was appropriate.
Dd1 wants to be a fairy. I actually made her a no-sew tutu from instructions I googled and found on youtube and it turned out pretty fabulous. We were going to make some wings too but when we were at Walmart they had some nice aqua coloured ones for $4. I wouldn't have been able to make them any cheaper than that. We did buy some gemstones for her to glue on and we'll make a wand at some point.