Depending on how handy you are you can build your own simple jig for very little money. There are several YouTube videos that explain the basic process/jig. One I found that seems cheap, and efficient is here link. The guy demoing the rig even appears to have carbon shafts like you.
The basic concepts that the videos tend to share is a fixed cutting wheel, some sort of aligning/mounting surface, and a way to measure the arrow. In the video this is accomplished by screwing a Dremel tool onto the jig's base plate. Two L-brackets are screwed onto the base plate at whatever distance is comfortable. In back of the L-brackets a cut-off yard/meter stick is glued to the base plate. Finally a block is screwed onto the base plate at the length you want to cut your arrows.
To use this jig you first trim the shaft down until it is close to the size you want. Then you place the nock against the block, and slide the arrow back against the L-brackets rotating the arrow as needed to complete the cut.
Keep in mind improvised arrow cutting solutions do not have many of the safety features of a commercial product. Use these at your own risk. Misuse or carelessness could cause serious injury to yourself or your equipment.
Alternatively for a quick and dirty solution you might just try a small pipe cutter and some sandpaper. It is unlikely this will result in optimal cuts, but for the truly budget conscious this might be an option.