1. Go to your local thrift shop.
2. Offer to buy all the poles in all lengths for 15 bucks or whatever number you make up on the spot.
3. Get hold of a pipe-cutter either buy one for 10 bucks or steal one from your dad.
4. Remove all grips with the power of heat, which can come in many forms, heat gun, dryer, steam from a kettle, etc...
5. Cut poles to desired length.
6. Put on the old grips with a dab of glue or go to 6a
6a. Get cheap bmx/mtb handlebar grips
6b. Layer some cloth tape on the pole until the grip fits over snuggly with a dab of glue
6c. If you want a strap with bike grips: insert a star nut in the shaft, it's just like sounding only more permanent.
7. Done, you now have an infinite number of poles for almost no money.