I just bought an apartment recently – paid in full last November. I did not need to provide any documentation in regards to my marriage status, but I know Chinese people do.
There is some running around in terms of getting documents together and there is almost no cost to that – you DO need to get a formal Chinese name now, though, which requires going to a notary and basically paying them to write up a paper saying you will be referred to as (whatever your Chinese name is) in legal documentation, and sign using that name..there is LOTS of signing/fingerprint stamping.
The biggest hassle in the process for me was getting the cash into the country and converted to RMB. The rest wasn’t that difficult. I imagine most higher end properties are allowed to sell to foreigners (they have a certificate allowing them to, you MUST ask at the sales office, make sure they show you a copy of it and aren’t just trying to get a deposit because you wont likely see that back :D)
Edit: Ben, re: the 1 year residents permit, I don’t think that’s the case any more.