Yep transformer set up in a voltage bucking configuration only has to carry the power of the relative input to output voltage difference.
....
metal halide, mercury vapor, or high pressure sodium lamp. They have power taps on the primary windings for 277, 240, 208, and 120 volts and make excellent buck boost auto transformers! You can probably get a used one, or possibly several of them, from a local electrical shop that services street and parking lot lights for next to nothing.
Otherwise the only fix for being a cheap ass is spending money, spending time learning, or spending time scavenging.
What exactly are you powering anyway?