If only used for pictures, low capacity is usually not that much of a problem. 8GB will still get you around 400 raw pictures. Those will start at around $ 15.
If you're taking video, especially raw video, where write speeds as well as capacity matter a lot more.. I would save up for something better :p in that case, you will be looking at around $ 50 minimum
Why silicon power and sandisk only btw?
If you want to go really cheap, this seems to be your best option
Komputerbay 16GB CF 300X
However, this seems a way better option in the longer term to me
Komputerbay 32GB CF 266x
Sorry to say I don't have any experience with the silicon power and sandisk ones.. I do own a sandisk SD card, which is fine.
Wondering why and how you got that 7D though :p
Thanks Ramon
I explained about the brands , sadly International shopping is not available in our country for now due to politics issues.
and about the 7D , i don't really understand your wonder
lots of people owns this beast and i picked it up as a second hand camera with a very good price.
but for now it's not with me and i'm using my 2years-old D5100 which is totally fine... ish
but of course ML is something else.
I will be doing Raw video but not quite sure how much speed does it need in FullHD or less (I couldn't find a topic for this matter)
and photos as well (more than video)
Kumputerbay seems to be a popular brand i heard it many times.