If I only buy one code, what does it get me in terms of:

Stacking Info
Each codes upgrades account
3 codes allows you use video background on the design
Access to over 5m stock videos to pick from
Gives you more storage capacity & share edit access to up to 100 people
Upgrades to 68 hours monthly animation render cap
Oembed support. Embed rich animated designs on your web pages. Specify display size and link.
Video chroma tool: Automatically replace video background.
Qrcode addon: Create and edit qrcode using the design editor.
Modify SVG colors.