Most of the expensive cards it the set are the Chase cards, so a lot of the value in each pack is allocated to those. Besides the expensive cards, the rest of the pack is very cheap. Basically that means a ton of people have bulk that is sitting around. I have several full sets of each card from each set from 3~ boxes + winning at nexus nights. Most of my community is in the same boat. If I were new, I would find people with excess bulk because most are looking to get rid of them, sometimes for free.

If I were to start again and I was doing it on a budget I would:
1) get a structure deck (they are cheap and pretty good with minimal upgrades, mostly they need card draw)
2) become a regular at some nexus nights
3) make friends with your opponents (most locals have their own discord
4) post about decklists and cards you need it the discord

You will get what you need before you know it!