Yeah, I feel that. If I was trying to get into the eternal formats I would probably do it in a very long-term and circumspect way. This doesn't apply to vintage, but in legacy I would probably buy a cheap burn deck/ red deck wins to play in the short-term. In the long term I would look to trade up.
I would go on ebay and try to find play-sets of trade-able cards for cheap. Example: A few days ago I get a play set of Avenger of Zendikar for $6.50, I traded 3 of them for a Cascade Bluffs and some junk rares, a $14 value. So in addition to trading up (any time you trade for dual lands like cascade bluffs it's trading up), I also made a reasonable profit in term of stuff I have to trade. There may come a time when I trade 3 Cascade Bluffs for a Tropical Island, a legacy staple. A couple days ago I payed $13 for 4 chinese Rhys, each is worth $8. It will probably take a long time for me to unload those Rhys, but thats okay because I stand to gain a lot when I do.
So instead of paying for legacy with money, I plan on paying for it mostly with time, it takes a lot longer may way then just with a credit card, but it's much cheaper. Also, invest in cards that will go up in value and avoid cards that will go down in value. Things that go up in value are cycles of lands that won't be reprinted, like the Shadowmoor filterlands, they aren't in standard and they won't be reprinted= long term holding value. One of my smartest investments was buying Seachrome Coast at $4 each right after Jace the Mindsculptor was banned (literally that weekend). Think about what metagame shifts will cause which cards to go up in value. For example I will, within the next month, attempt to sell or trade my Seachrome Coasts at $17 each before it gets too close to rotating out of standard, and as soon as Consecrated Sphinx rotates I will try to get them because right now theyre price is too high to be worth while.
Just some thoughts, and I hope you are able to get into vintage, it may be worthwhile for you to look up Pack to Power strategies.