I have a Canon EF 70-300mm f/4-5.6 IS USM, due to my own rushing, it fell off the camera to the gravel below. I took it in for an estimate and I was told the "guides" are shot (thus the barrel sags down when extended from the body) and it has a $320 repair tag, for a $450 lens (brand new) it seems too much for me. Apart from a doorstop or mini shot put, any ideas of a use or perhaps even a way to get it repaired on the cheap? Thanks.
Unless you can do it yourself there are no cheap lens repairs. It takes the same amount of time and expertise to disassemble, repair, and reassemble a cheap lens as it does to do so with an expensive one. With regards to repairing an existing lens, the only difference is the quality of the glass and other parts that the lens is made of. If replacement parts are needed they might be more expensive for a higher quality lens. But the labor cost, which is the primary part of your $320 estimate, will be relatively the same.
Consider getting a quote from Steven Lee, Camera Hospital, Beencoolen street, Singapore -
Camera hospital website here
I have personally sent cameras and lenses from NZ for Steven to repair, so this option is possibly a viable one for you.
He's good, honest, friendly (although sometimes little spoken) and about as cheap as you'll get. Slow freight both ways and it may be worthwhile.
The shop is small (aka tiny) and contains vast numbers of cameras, some for sale and many for display. A most interesting place.