Try 2 reed relais in combination with a bistabile relais (two coils) with a magneto as a switch. Drain would be nil.
When the magnet closes 1 reed relais power is fed to one coil of the relais. When the magnet is removed power is cut to the coil but since the relais is bistabil the contact remain in place until the second reed relais closes and powers the other coil to switch off power. Very much cheaper and smaller than the keytransmitter option.
You could also try a variant with IR leds and photo transistors if you want. There are many possibities here.
You don't stop playing because you get older,
you get older because you stop playing.