Under deflation prices are falling - by definition. What you say ("he/she will simply increase the price for the work he/she is making") breaks this definition, that's all. It does not matter if you need something, what actually matters is the price you are ready to pay for what you need as an "aggregate" consumer (not you personally). Again, under deflation you are not ready to pay the price the producer initially asks which forces the prices down (and leads to all ensuing devastating effects on the economy) - all strictly by definition