I bought a used fat bike off marketplace for $300, a spring front fork for $80, hydraulic disc brakes for $80, a Bafang BBSHD mid drive kit for $1300. I am still less than 2k. I plan on adding a geared rear hub but they are nowhere to be found right now. First gear is 42/34 at the moment.

If I change the hub to a cassette hub, I can rearrange the sprockets and drop the front 42 to as little as 28 for a super low first gear but honestly it doesn't need to be that low. I've been riding mountainous mountain bike trails taking my dogs squirrel hunting and it has done a wonderful job. Currently weight 72 pounds