I found tons of beauty recipes from facials to toothpaste.
You can also steam it or boil it, let it cool and then separate the oil from the water. I swear when I was looking into making oil from my lilacs there were little stovetop set-ups for extraction, but I haven't found them at the moment.
Just a thought after looking at some of the pricey stills for homes..
Someone correct me if they've tried this and it didn't work. I'm thinking your quality or quantity might suffer some, but not substantially to offset cost difference. What about one of those kitchen steamers? Use distilled water. Set it to max water/time. Put the chopped mint in the basket and turn it on. After it's done, let water evaporate and collect the oils from the drip tray. You can pick up those kitchen steamers pretty cheap.
I make mint juleps with mine. Boil a cup of water and cup of sugar until the sugar dissolves then dump in the mint and let it steep. The longer the better. Then strain out the mint. Pour some over ice cubes and add bourbon. Perfect. You can probably use that mint syrup over other things too. Fruit comes to mind. I also add fresh mint to my tabouleh or you can throw it into the bath after gardening. It is very refreshing but you come out with leaves stuck to you. Enjoy!