New- $100-130. I think Apple has one for $109 and $129 with built in dust collection.
Some people make them out if a Dremel and some way to measure the arrow (wood channel or angle iron).
Other have made them out of small cheap chop saws like from harbor freight, but not recommended...
For just over $100 get a commercial one and have now worries. Key is a smooth square cut. Squaring tool is not a bad idea either... See G5 ASD.

No problem- that's why we're here!
Here's a link for the arrow saws I mentioned: http://www.bowhunterssuperstore.com/arrow-saws-apple-archery-c-24_113.html

I have that arrow saw, from that supplier.  Love it, works great.  

I also have the arrow squaring device from G5, also worth the purchase.

In these days of internet shopping, you can often find arrows for what components cost to make them yourself.  The problem is that nobody will put as much care into making your arrows as you will.  You then have the ability to repair your own arrows, experiment more with fletching combinations (really handy when broadhead tuning), and get exactly what you want when you want it.

If you decide to start building your own and have any questions about it, fire away.