It all depends on where you live and how good you are. I’m an architect myself but you don’t need to be one to work in the industry.
I’ve worked in the US and Australia and I’ve charged around $2000 per still and $7000-10000 per minute of animation.
I’ve heard big guys like MIR charge $8000 to $10000 per image! not 4000 euros I know because my office tried to hire them…but anyway, you gotta be awesome to charge that much.
The thing is the market is very competitive and many people from the third world (like me) usually charge less than the minimum in other countries. But if you’re good clients will come.
I usually ask for 50% upfront, and the other 50% at “completion”. There will be A LOT of changes, I include 2 or 3 rounds and after that it will be charged.
Finally, no. The client will never have the rights under your source files. You provide a jpg and or an avi and thats it. They can always buy it from you but it would be costly.
Build a very strong portfolio and you’ll be in
Good luck!