You've received some stellar answers already ... I echo all of them.
Here are a few more nuggets to think about:
1. Never spend your principle (and then of all things invest it into something that costs money to own and most of all maintain-there is always sumptin':)
However, I happen to be one of many who prefer homeownership, period. No math examples in the world will ever convince me that owning your own home and garden isn't the most awesome thing in the universe and oh so worth it:).
So if you are really freaking and genuinely prefer a home of your own, you might consider taking out enough for a 20% deposit.
You know - your lifestyle and how demanding your job is should be a consideration as well. If you know that you can expect a transfer in a year or two across the country - then think twice, absentee landlording is the devil incarnate.
Why would you spend big bucks on something that you have no time to enjoy yourself and worse will only vex you when you need to spend $10K plus for a new AC system or whatever.
Even if you only rent a room to help pay the mortgage there can be trouble with the person who rents from you while you are in the middle of an important project at work that will define your career.
If you are thinking of Real Estate ownership and not really a home - you might want to consider a duplex or a home that you can rent out at least partially in effect letting someone else pay your mortgage for you.
Think of it this way, if you sunk all your money into a property and then find that new higher property taxation and needed improvements keep you from saving as much as you really want/need to in order to reach your stash goals ...
Until you've actually made time and took the effort of looking into the real estate market - you may be surprised what's out there or not, the desirability of the neighborhood, safety, school district - actual availability in your price range - is it suitable for renting, is there restrictive zoning and so on.
There is a lot to consider, family, suitability for future kids so you aren't forced into an expensive move down the road.
You are right - you need to think this through and know what your goals and expectations, plans for your future are.
2. TIME and the magic of compound interest have been in your favor, remember you can never ever make up for time.
You have a great start and a nice amount invested don't destroy it all - you can never buy back or save enough again in your fifties for what you did not do or take advantage of in your thirties.
Play with your $300K and see the difference in investing in your thirties - forties - fifties -
despite the ups and downs if you have time on your side you are golden.
Don't give up that ace in the hole.
None of us know what the future of the stock market holds - it may all go to hell in a handbasket, the current virus in China could somehow get out of control and wreak untold havoc upon the world and we will all be in trouble for decades to come.
There is no timing the market.
Yet, diversification is a good thing too - so consider your options carefully.
So much depends on your situation and your area - our housing market is red hot, always a scary time to buy IMHO, but again what do I know? Those prices may be here to stay and become the new normal for several good reasons.
Personally, I like the idea of owning property and having a renter pay your mortgage - it gives you some diversification and you don't have to worry how you'll pay the rent/mtg when you lose your job.
There is risk and luck in everything you do.
