Thinking you can read Fama papers to take on quant funds, like smabie is claiming at several places in this thread, is like reading Commodore manuals to take on AlphaGo.
It's kind of like the theory that open source doesn't have serious bugs because so many people read it.
You know the saying that the market can remain irrational longer than you can remain solvent? If some people don't care about doing simple analysis, and others assume that someone else is doing it, and still others accept that it's useless to do it if other people aren't, it seems like a none-too-efficient market can be a stable equilibrium.
There's a reason why these factors are called "persistent." For systemic reasons, it is hard to arbitrage them away, mostly due to laws, and sometimes tax implications.
Of course, I suppose it would be possible if you discovered some amazing alpha factor. But if you did, you probably would be better just trying to get investors.
So in short, the answer is $0. For my personal portfolio, I run (only started recently) a variable leveraged beta strategy that can be described in my three part series:
https://cryptm.org/posts/2019/10/04/vol.html
Now that I have my alpha factor I backtest it and whatever. Since the mean of a zscore is zero, I know I'm market neutral, so (ignoring some stuff) my factor should have little exposure to the market.
If I think it's good, I add it to my other alpha factors and combine them somehow. Could be as simple as adding them all up, or maybe something like using random forests to figure out the best way to combine them, or whatever. Now that I have a bunch of alpha factors all combined, I can run them through the optimization engine.
The optimization engine will adjust the weights of my "ideal" portfolio in order to reduce exposure to various risk factors (thus lowering volatility). My optimizer will also figure out how often I need to rebalance. There's generally a bunch of terms in there that try to reduce trading costs and zero out exposure while not diluting the "ideal" portfolio too much (or else the alpha could be wiped out).
Now, after all of this, I'm ready to trade.
In short, what we're trying to do is reduce our exposure to as many factors as possible and just get exposure to our alpha factor. We don't want the market, price of oil, sex scandal of a CEO, or anything else affecting our portfolio. We are trying to dig up this latent, unearthed, alpha that exists in the market, but doesn't belong to one company or asset.