You are right, but regarding the 500$ example, I was referring to the multiple factor, there's a much higher chance for a cheap coin to double in price than BTC to double in price, for example, I put 1,000 USD on verge when it was 0.005 USD, that got me 200K XVG. After XVG reached 20 cents, I sold 100K verge and was able to buy 1.4 BTC with it, and still have 100K XVG left. If I put that 1,000 USD on BTC, it would take quite a while for it to make the gains like a cheap coin. BTC will be like Godzilla, a very powerful yet slow Asset that stays hidden in a mystery realm, so it will be a great store of value, literally Digital Gold.
Same goes for Ripple, much higher chance for Ripple to double in price than BTC, that is why people invest in cheaper coins, so they can eventually return larger amounts of BTC. I am not against BTC at all, but I am actually holding over 24 different coins now and it is helping me get 1 BTC every now and then :) it is just the multiple factor is the most effective here in Crypto world.