Decent Spotting Scope Can You Buy A Decent Scope For Bird Watching For About $150?

Can you buy a decent scope for bird watching for about $150? - decent spotting scope

I need a compact telescope with 20 times the power. The main objective to observe birds. The second objective is to fire at 25-50 meters with a caliber rifle, 177 air to detect.
You are MIS 1 of 2 ways:
http://www.opticsplanet.net/tasco-20-60x80-world-class-spotting-scope-wc206080.html
http://www.opticsplanet.net/tasco-world-class-spotting-scope-20-60x80mm.html
Because they target the big 80mm, but I prefer a prism BK-4 on BK-7 prism, but that would double the price and make it out of my price range.