Survival instinct is really hard to overcome. You're a new user, you just joined, you're debating which one to get, you may not be at that point where you are likely going to be able to overcome survival instinct easily. Committing suicide, or attempting (and failing), is, for most people, very very hard. And I said that as someone who failed an attempt. Also, I could be wrong, some people do commit successful suicide attempts quickly without hesitation... but a lot of people can't, a lot of people fuck up their attempts, and for most people it's very very hard to do it. Most attempts fail. Plus, this is a nice forum, we're not judgmental, and many of us are also very depressed and sometimes it's easier to talk to other depressed people.
i'd say get the computer.
Bonus: computers are fun, RAM and SSD prices keep going up, so get the extra RAM and SSD space now, before it's too late. You may be dead in a year, you may be dead in a 2 years, or you may be alive in 5 or 6 years or even longer. A lot of people are suicidal for a while, at least usually over a year, before they can do it. Not everyone... some people do it fast... but... why not stick around on the forum and get to know people and get the computer?
The shotgun will likely come down in price slightly over time or stay about the same while there is a real SSD and RAM shortage that is affecting the entire world. It makes sense to buy the computer first. Do the financially logical thing and get the computer...
Don't take it from me, take it from @EmptyBottle, my other personality who is only active during the night time and supposedly lives in "Australia" and also knows about computers.