You will save plenty of money by making your toddler's costumes on your own. The best place to get cute patterns is at your local JoAnn craft and fabric store.
No halloween costumes for toddlers are not available year round. But you can find costumes year round on the internet.
One great site to find patterns and directions for making Halloween costumes for kids is Family Fun. You can find them at http://familyfun.go.com/halloween/halloween-kids-costumes/. Another good resource is http://www.allcrafts.net/kidshalloweencostumes.htm. I also recommend that you check out http://sewing.lovetoknow.com/sewing-patterns/halloween-sewing-patterns for a list of places to find free patterns.
To find a toddler costume, try looking at Halloween Express. They carry costumes in their store so you could try it on and make sure it fits. They also carry costumes online which allows you the convenience of internet shopping.
A great place to find cheap costumes online is on e-bay, I also suggest trying Kijiji you never know what you might find there. You could also try http://www.costumecauldron.com/shop/halloween-costume/TODDLER-COSTUMES-title0-p-1-c-58.html They have a great toddler selection and many costumes under $30.00.
Newborns need size 0-3 months. You can find information about newborn costumes at the following website: www.cradletokindergarten.com/baby-toddler-costumes.html
There are so many different costumes for little boys to wear. A lot of these costumes are easy to make, and you can find tutorials on how to make them online. One costume you could do yourself is a coyboy.
The most common glow in the dark costume for Halloween would be a skeleton whose bones glow. These are available in sizes from infant to adult. You can also easily find many other costumes that glow like aliens and witches for your toddler.
Patterns for children's ghost costumes are available online and from Halloween stores. A person can order these patterns and create their own ghost costumes for their children.
WalMart has a wide variety of warm costumes for younger kinds. Things like a lion, or cowboy (where they can wear jeans)may be a more practical costume if it happens to be cold on Halloween.
One can find a wide selection of sewing patterns at sewingpatterns.com. On the site one will notice the different sewing patterns ranging from tops, pants, skirts, jackets, dresses, costumes, children, and babies.
You can find a police costumes on websites such as www.3wishes.com, www.costumeexpress.com or www.spirithalloween.com. Also, you may try making your own from items around the house.
At your home make costumes that you like from tv or books if you don't know how find someone that is really good at making the costumes. Good ideas for costumes are naruto character costumes or any other costume you like.