agree with Steve, I would buy two from 7dayshop and still be
quids in! I use them with no problems and the only difference
would may be a very slightly shorter use time before it needs
recharging.
I’ve been using a Hahnel battery in my 350D that I bought from Warehouse Express if I remember correctly. For me they fit in the happy middle ground price wise and provide a similar capacity and usage time to the Canon battery. Nearly two years in and its still going as strong as the Canon battery that came with it so I would definitely recommend them.