Buying an investment property - is it a business expense?

[Emily T.]

My unrelated personal business has taken off and I may be looking at making $500k this year. I own no real estate. I've never made this much money or even close. I need to get rid of some of this cash so I'm not paying cray cray taxes.

Can I purchase an investment property, like a small apartment complex, and do it through my business, using the purchase price as a business expense?

So, make 500k, buy 400k apartment complex, only pay taxes on 100k.

My tax person is saying no. Bummer.

If not, other advice?