。
She bought the old table for next to nothing.
Literal
She [topic-は] that old table [object-を] free-equivalent [for-で] bought.
ただ同然 (lit. 'equivalent to free') is the bargain-hunter's stock phrase for 'practically free, next to nothing': ただ ('free, gratis') + 同然 ('equivalent to, just the same as'). で here marks the price of the purchase — buying-at the price 'next-to-nothing.' 同然 also appears in expressions like 死んだも同然 ('as good as dead'), 子供同然 ('as good as a child'). Old tables and other vintage furniture often turn up at unbelievably low prices at リサイクルショップ (secondhand shops) or 蚤の市 (flea markets).