I have a hartke 60w bass amp right now, some one is offering a Behringer BX1200 120w amp and 30$ for a trade. I know behringers have a bad rep, but am I wrong to think this is a good deal?
Only in the sense that you'd probably be able to flog it for $40 if you tried.
Keep the Hartke, it will be a better amp and you will get more joy in using it. Save up an get a decent amp if you want a higher wattage.
The Behringer probably won't be much louder anyway.
the Hartke is a better amp, hands down.