I used to use a "2" gallon Zip-loc baggie as a rain cover. Cut a slit in the bottom of the bag where the crease is that is slightly smaller than the lens hood. Then slide the camera in through the zipper end so that the slit you cut will now stretch around the lens hood and seal it. This provides pretty good protection for the camera and lens, the stiff zipper part (I preferred it in a horizontal position most of the time) of the bag keeps that end somewhat open and you can reach the controls to operate this pretty easily, including getting up to the eye piece. I found it worked really well when using a monopod, thread the monopod on right through the bag, that way the bag was not moved around much by handling it too much. I used it for several years in some pretty bad downpours and never had to worry about the camera or lens.
While I'm sure that will work great since I use to pretty much do the same thing with my compact before I got a DSLR, I was looking more towards a permanent solution.
Dude, you're either going to have to put out some coin, or deal with a "disposable" solution. There's no such thing as a free lunch.
I used to do something very similar to Tony S here. Same 2 gallon bag. Difference is this. I wouldn't cut a slit, instead, I'd put the camera in and orient it how I'd like it to be in the bag. Then, screw down a filter through the bag. Then carefully back the filter off. The filter should cut, or mostly cut a lens sized hole in the bag. Take the hole you just cut out, if you need to, you can carefully use scissors to clip the parts that might still be hanging on. Then, place the camera back in the bag, and screw down the filter again. The bag should stay in place. You should also be able to put a lens hood on through the bag, which will do two things. 1) Help hold the bag securely. 2) protect the filter from rain spots.
I live in Sitka, AK which just so happens to be one of the rainiest places in the entire U.S. Using this method, I've never had a leak and always had a dry camera. Just always kept a box of 2 gallon ziplocks with me.
And for those who like trivia and want to understand my experiences with rain, Mobile, AL is considered to be the rainiest city in the US with an average rainfall of about 67in. Sitka, on the other hand, gets around 85in a year. We get, on average, about 180 days of rain per year. If you can't adapt to the rain here, you'll have a tough time being a photographer.