If you show up to play a round of golf, and your opponent has a nice set of professionally-made clubs while you're using some sticks you carved by hand, you're probably going to lose, badly. But that doesn't make golf "pay to win" -- at the competitive level of golf, everybody has made the investment in that baseline of good equipment, and you're back to practice and skill as the differentiator.
Magic is similar. If you show up to a constructed tournament with whatever you could cobble together from a few booster packs, yeah, you're going to get crushed by people with competitive decks. But at the competitive level, everybody has made the baseline investment to have access to the full card pool, at which point you're back to skill (of designing/choosing/playing decks) as the differentiator.
Anyway. Top-tier Standard decks are in the couple-hundreds-of-dollars range, and even if you just go out and get the cards for one of those decks and nothing else, there's enough value in the cards that you can trade/sell and get back not 100% of what you paid in, but enough to make switching to a different deck not all that bad.
Standard: $500 per year (more if you have to buy into a completely different archetype)
Modern: $1200 per deck (with a revolving door on the ban list)
Legacy: $2-4000
Vintage: $15,000+ (mint power mox and lotus would cost $35k+).