Charcoal is probably more cancerous than gas [citation needed], but definitely tastes better I think to have that flavour. You definitely don't want a George Foreman or something dumb like that cuz they are a bitch to clean, you wanna scrape the metal while its still hot and the flames are dying.
Realistically since its just you and your bof you can get something like this for $20 at the local wal-mart
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Bag of charcoal will run about $10 and last you maybe 5-10 grilling sessions. Make sure you get lighter fluid too. I think it prolly balances out in cost with gas because even then are still paying for the fuel.
ADDENDUM get a chimney starter cuz half the fun of grilling is lighting the fire