Some 2 years ago I did something stupid, someone left me negative feedback because I didn't have liquid BTC to settle a deal. I pigheadedly decided to buy positive feedback paying with BTC (also becuz I thought anything goes including reselling accounts). Got a tonne of negative feedback about it. Haven't posted much later on. Not in the market for anything currently but I wonder if you can only deal on the Marketplace if you have a pristine positive Trust record.
If you do want to trade, use an escrow.
Other users then shouldn't have a problem trading with you, in spite of your negative trust.