I see lots of advice here, all posted with good intentions although some with less experience than others. So, let me give my advice. To back up my advice, I was a Realtor for 16 years and my father was a Realtor for 36 years. I have been personally involved in over 5,000 Real Estate Transactions. My father has been personally involved in over 10,000 Real Estate Transaction. We have a Family Trust that owns property in California, Texas, Colorado and Virginia. We are currently looking to buy in North Carolina. Several of my extended family have a six figure MONTHLY income from real estate investments. So let's start with the basics.
Your son will have to pay rent no matter where he lives if he does not own. The upside of renting is that you can move quickly and you have someone else make most of the repairs. The downside is that you are not building any equity, you can't make changes to the property for your own benefit.
If you own a house, the benefits are numerous. First off, you get a tax break for mortgage interest paid. Next, you can make changes, additions, upgrades and enjoy the benefits of them. Home ownership also gives you other perks like reduced insurance premium costs on autos, life, etc...
If things do not work out, your son can either rent the house or sell it. If he can rent it for a positive cash flow, it is a good investment. If he has to sell it, he make have a loss but you have to compare that loss to what he made with tax savings.
With the current real estate market being down, it is a GREAT time to buy. The prices will have to turn around, even if it takes five years.
Let me give an example. My wife and I bought a house in Texas two years ago. We paid $103,000.00 for the house. After putting 20% down, our monthly PITI payment is $848.00. It is currently rented for $1,071.00 a month. So looking at the tenants, they paid $12,852.00 in rent last year and have nothing to show for it. We put $20,000 down and made $2,676 the first year which is 13%, not counting any appreciation or tax breaks. So, whose position looks better, the tenants or us? As a side note, we have NEVER even seen the house nor do we plan on ever seeing it.
So let's say you sell your collection and give your son $10,000 for a down payment. He buys a house for $100,000, gets a $90,000 mortgage with an $800.00 PITI payment. If the price of the house goes up $10,000, your son will have doubled his equity. If the price of the house goes down, he is most likely paying LESS with a mortgage than he would be if he were paying rent.
As a final note, I think the house has a better chance of appreciating than the coin collection. As a matter of fact, there is a good chance that in ten years, the equity in the house would buy your coin collection back, five times, maybe ten times, over.
Just my humble opinion.