Originally Posted by Rowdy
I too never regret investing in glass as well, properly treated those lenses are going to last a long time! bodies however come and go. Its a rough one! From your personal experience, how well weather sealed is your 5d3? It gets pretty wet here in Vancity
I used my 5D MkII in light rain and heavy snow with no protection and no ill effects. It worked well down to -14F. I'd expect the MkIII to do as well or better. In heavy rain you'll need a raincoat for it. Art Morris, over at birdphotographers.net knocked two 1D bodies out of service using them in soaking rain without protection, so I don't think it's wise to rely totally on weather sealing; however, I have no problem using my 5D MkIII or my 7D in light rain and/or heavy snow and extreme temps.
Yeah, any body, even a 1D, will be worth $500 in the not too distant future. Pro lenses, OTOH, can actually appreciate and seldom lose more than 20% of their value.
The investment difference is so great that you might want to rent a 5D MkIII for a week to see if it can fulfill your needs. You'll be blown away by the AF, I predict.