After much research, looking at what I wanted, verses what I could afford I finally broke down and bought a new telephoto zoom lens. A Sigma 50-500 f4-6.3 . Yes I can use a teleconverter with this one, my current lens (170-500 I can NOT use a teleconverter with it) It has a lens lock, and well its only a year old compared to the one I currently have that's 8 years old, and very slow, not to even though I've tried to take care of it, it has been damaged. Thus not because I just wanted a new lens, I NEED a new lens, so I got one that will cover everything. Sure it doesn't have the VR reduction, but with a monopod and tripod, I have a feeling more photos will be keepers than not keepers. But what it really came down to was price.
The New Sigma 50-500 with VR was 1600.00, and the ones I'm looking at on Ebay are about 600-700.00
Couple that price 720 (BIN) with a 10% discount, yeap a 72.00 saving, even after shiping I get a better deal than I could anywhere else. So a new lens, and a new UV filter is on its way to me, and I pulled my filter off Ebay, polarizer, because its the lens that I am getting is the same size that I have now. The new Sigma 50-500s are a 96mm lens and yes the filter prices reflect that size.
I can't wait to get out and get some new photos with my new lens.