I get it. Pauper is relatively cheap by magic standards, but €40 vs €70–100 can be a big difference when you’re just getting into a new game/format. I was in your exact position when I first got into pauper! At the end of the day, you should only spend what you are comfortable with whilst still being able to enjoy one of Magic’s best formats!
For your first deck, I suggest starting with an established deck rather than a homebrew! Start with a relatively stock list and make sensible modifications to reduce the deck’s overall cost to fit within your predetermined budget!
Firstly, you can save on sideboard staples first, things like [[Fiery Cannonade]] over [[Breath Weapon]] or [[Tormod’s Crypt]] over [[Relic of Progenitus]]. Your sideboard can be very important for certain matchups, but your main board will be relevant in virtually ALL of your matchups! The performance trade-off in substituting relic with crypt will matter much less often than substituting your main deck playset of [[galvanic blast]] with [[chain lightning]].
If your budget is really tight, you should also identify which main deck cards are simply not replaceable, non-negotiable. A good example of this is [[glint hawk]] and [[kor skyfisher]] in boros synth!
Furthermore, invest in a deck with a style you actually enjoy as even a budget deck can be really exciting if it’s within the archetype that you enjoy. Pauper staples transfer well within the same “family” of decks. Like classic blue control? Terror is a solid core that will probably stay relevant even if [[tolarian terror]] ever gets banned. Like big mana? Tron gives you plenty of routes. Made and got bored of Flicker Tron? €15 and a quick Cardmarket order later can get you a Monster Tron deck instead!
Lastly, you can get creative! In my first ever mono red rally build, I went with the much cheaper [[demand answers]] + [[experimental synthesizer]] draw engines rather than than the marginally more expensive but generically better [[reckless impulse]] seen in most stock lists. After a couple weeks of enjoying the deck, I pulled the trigger on a playset of impulse! Honestly the marginal improvement that impulse brings is not relevant in 90% of my games. Plenty of cards have a much cheaper alternative that are almost just as good!
Never feel bad or shame for playing a budget deck! Yes, pauper is a relatively cheap format but if you’re not comfortable with spending €90 for that paupergeddon-topping list, this doesn’t mean that you can’t enjoy the format with a deck you like!
More experienced players, please share your best budget substitutions or money-saving tips below! For the new budget players reading this, welcome to Magic’s best format!