Oh, I see, the all lowercase confused me.
I believe he wants to use a low frequency power transformer, like an old school inverter. The problem is he also wants it to be cheap. A low frequency transformer is not a cheap option, which is to use a high frequency ferrite transformer, running at a much higher frequency and a rectifier and filter, to make a DC:DC converter, followed by an H-bridge to make an inverter. The extra cost of the more complex electronics will be outweighed by the smaller, lightweight transformer.