Yeah normally I don't care about this or that hot deal, but as a fellow birder seeing the 800mm was a gut punch. (I don't think anyone handholds that one, at least not long)
I've been kicking around ideas on how to save up for one of those L lenses. At $20 a month it would take me about 7 years to save up for the 100-400 model. Maybe getting something used from a lens rental service might be a better shot.
If you're on a tight budget a past-generation model is the most bang for your buck, perhaps the 400mm f/5.6 or an older 300mm f/2.8 plus a teleconverter. I had a 100-400 for a while and I wound up shooting exclusively at 400mm, so it was kind of a waste of weight & cost.
Also, glass is more important than body, but you might be able to get more stops for your money with an updated body, e.g. if your current body is only good to 400 or 800 ISO. IMO on a budget you should get the best f/5.6 setup you can and then look for a body with high ISO.
