Just deadlift.

3x per week. Start with an empty bar, then add 5lbs to the bar each time you deadlift. Once it gets so heavy that you can't add anymore, just back off to 1-2x per week and maintain the weight on the bar. It'll take you about 20 minutes each time and the bar and plates will take up about 4 square feet in your living room or garage when not in use.

Here's how you deadlift: https://www.youtube.com/watch?v=VGZrATR1O4E

You can get a barbell and plates on Craigslist for $250. If you decide that it ain't for you, you can sell your barbell and plates on Craigslist for $250. So there is no financial downside. But it has the potential to be the best $250 you have ever spent. On anything.