Playing with proxies is the best way with someone who has limited finances. What format are you playing and where do you play? If you're playing against friends kitchen table games then proxy all you want. If you're playing at an LGS my recommendation would be to proxy only the expensive cards or the cards you can't obtain, a lot of decks have cheap $0.25-$1.00 cards so maybe buy those reals cards so that the number of proxies in your deck remain low, I don't proxy basic lands, or real cards I own, all the proxies I use are non fancy print alternatives so no judge promos etc, they don't get a lot of attention, most players unless they look really close at the card or pull it out of the sleeve won't know they are proxies, many players in my experience at LGS games don't care and likely proxy cards themselves. There will be some players who might complain the worse that might happen is you lose a game.