Internet Security 2011 Renewal Disk vs Internet

Last year January I bought a 1 year Norton Internet Security 2011 disk for 3 uses which I used one for me and one for my daughter who lives at my address, installed in February.. It is now time to renew. Very happy with Norton but, do I need to renew over the internet or can I once again purchase a 3 user disk and install using the disk on our two computers? Also, is one method much easier than the other? I can pick up the the 3 user disk at my local BJ's on sale for $30 (same as last year) verses $50 via Norton renewable website, both reduced from $70 retail. I'm not that concerned over the $20 (time and gas saved using the web) but feel more secure with a disk rather than messing with a download over the internet. I am not that familiar with computers and last year I recall was quite easy using a disk for my first introduction to Norton and deleting the other company.