Everything in my house was given to me, all of the furniture that is. I refuse to buy furniture, but I realize that not everybody has furniture that can just be given to them. Another reason I hate to buy furniture is because it depreciates so quickly, especially the cheap IKEA crap that's made today. Don't get me wrong it serves a purpose, but it definitely isn't made like the strong oak furniture made in the old days. I've got two desks that were owned by my grandmothers and they're still as stable and strong as ever. And I'm sure they're worth way more now than they used to be!
So this is a situation where paying more for an item in my opinion makes sense. Filling your house with antiques that you NEED (not want) in my opinion is a good investment as long as you get a good deal on them. I'd suggest you read some books on the subject and befriend a gay man who knows something about them. Ask to go "antiqing" with them sometime to see what they see and what they recommend. They'll love you for it!
If you're somewhat handy you might also want to look at restoring some of them as a side business. Don't go crazy with this, but you could literally use your living room as a display case for your show pieces. This will provide you with functionality and fortune!
Comb through craigslist, garage sales, etc in order to find the best deals. Happy hunting!
PS - If you find that you've spent a decent amount of money on antiques than be sure to note and take pics for your insurance claim in case there is a fire or water damage.