$5,000 isn't actually too bad. At some points, acquiring a DASH Masternode was somewhere in the order of $100,000.
If you actually look at the amount of ETH held in the average ETH wallet, you'll find that a large number of Ethereum holders are actually wealthy enough to participate in staking.
I personally wouldn't want to lock up $5k just to secure the Ethereum network, unless the staking rewards were pretty lucrative (e.g. 10%+ per year).
Ethereum is too volatile to lock up for long periods.
Actually at some points (early 2018, to be exact) a Dash masternode was over a million.
Which is why staking/rewards doesn't mean a whole lot to me. I mean, what good is 5-10% a year when a coin can lose 90%+ of its value? It's not quite the same as bonds. If I had 1-1.5 M worth of Dash, and it's now worth about 75K, I wouldn't think to myself, "Yay, I got 5% in rewards for the year." I'd be grumbling about losing over 90% of my investment.
Although in a bear market like we are currently, staking rewards are at least something, assuming folks invest at the bottom. I don't view 5-6K as being too high a price to stake. But as I understand it (and I may understand it incorrectly) for the first year or two there will be two ETH blockchains, one staking and the current one. And if you decide to stash away your ETH to the staking chain, it's sort of locked there until the next dev stage.
Which means it might be an opportunity for the coin to pump with so many coins locked away. Or none of it will matter and the markets collapse... who knows...