There are many sites to give you cheap ideas. Some of them are www.halloween-website.com/decorating.html and www.bhg.com/halloween/outdoor-decorations/
Some of the cheapest Halloween decorations are the ones you can craft yourself. One of the best and most traditional ideas is to carve a jack-o-lantern.
Making your own Halloween decorations can be a lot of fun and it doesn't have to be expensive. Some great places to get ideas are http://iblue.hubpages.com/hub/Top-10-Halloween-Homemade-Decorations, http://familyfun.go.com/halloween/halloween-crafts/, and http://www.squidoo.com/halloween-homemade-decorations.
Check out www.partycity.com. They will have all kinds of halloween decorations, costumes and much more. They also provide low prices and shipping. Also check out www.HGTV.com for ideas on Halloween decorations and where you can get them from.
Some of the specialist Halloween sites offer good lists of ideas, hoping to lure you back to purchase later. Alternatively, various lifestyle sites do occasional posts, for example: http://www.moneycrashers.com/cheap-DIY-Halloween-decoration-ideas/
Good housekeeping and ehow have many ideas with christmas decorations from halloween decorations,Martha stewart also has great ideas for halloween decorations to christmas surprises.
You can find alot of good ideas for arts and crafts online. A good site for easy Halloween Decorations is http://familyfun.go.com/halloween/halloween-crafts/ Good luck with your students hope you can find something that you and the children will enjoy.
Halloween decorations ideas are all over the internet. You can look in magazines close to the holiday also. The internet is most resourceful if you are looking to get ahead start. It also supplies cheap, easy, at home crafts you can do on a budget.
You can find new ideas about decorations for halloween from books. WalMart is a store that sells many items online. You can purchase books from WalMart and they will have it delivered to the store for free or to your home for a nominal cost.
Outdoor halloween decorations can be purchased in you home town. Places such as walmart and target offer great halloween decorations for all sorts of decoration ideas.
Visit www.HGTV.com. They really have a lot of good and clever ideas for holiday home decorations. They can also provide you with some fun ideas for making decorations for halloween as well.
I like shopping at Kmart, Target, and Walmart for outdoor Christmas decorations. However, their stock may not be out yet. Check their online counterparts or Amazon for some ideas.
There are some places online that offer ideas on double-use ornaments. One site that I like is http://tlc.howstuffworks.com/family/halloween-decorations.htm.