If you are fond of mirror lenses, the Trending eBay Deals have something of potential interest, especially if a Canon shooter. The 47th Street Photo eBay store (99.2%) is offering the new condition Opteka 500mm f8 HD mirror lens. Included with that is an Opteka High Definition 2X Telephoto Converter (which is why the eBay listing says 500-1000mm f8), along with an Opteka T-Mount Adapter for Canon. The 500mm lens includes a soft pouch and three rear-mounted filters (two NDs and Skylight).

All that for $90 with free shipping. The 500mm lens has a 10 year warranty per the eBay listing. Over 690 units got sold so far from this eBay listing. The seller has a 60-day return policy but RMA must be issued within 45-days after purchase-date. Shipping charges not included/refunded.