I was lucky enough to find an old disc at a farm auction and bought it for $10. Best 10 bucks I ever spent. Works great behind my atv and for my needs, tight spots, its about all I need.
While I won't begrudge a person the right to sell equipment, sometimes, it's not the right thing to buy, depending on your situation and bank account. I'd rather sink more money into lime and fertilizer than expensive equipment.