I’m thinking on splitting my money for a Mac Mini M4 with my friend. Any advice?

I just sold my retro video game collection and got C$450 out of it. Afterwards, my friend offered to split for a new Mac (480 x 2=960). Since we are splitting the budget is C$960 for that price. I am able to buy a base model Mac mini M4 of 16 GB of RAM and 256 GB of storage, but the plot thickens. Because this is a “new Mac“ I cannot “tinker” with it. Meaning that I am unable to upgrade the storage up to 2 TB (which cost C$400). A single storage upgrade from Apple is going to be costing $300 extra making my total to C$1095. However, the base Mac mini M4 with no storage upgrades costs C$780. Can somebody give me any advice? I’m planning to do 4K video editing with Final Cut Pro shot on my iPhone 13.