As with most others here, the coffee quality is my driving force. Having said that, I typically pay $7/# for greens and $16/12oz for roasted. One pound of green seems to pretty consistently match 12oz of roasted, so we're talking oranges and oranges. I purchased my Behmor 1600 in 2007 and upgraded it later to the plus version, Total expense for roaster is about $400 then. I consume really close to 12oz per two weeks because I'm out of town every other week and have to purchase my americano from a road side vendor. I also do another 12oz per week for my wife, who stays home and needs her caffeine fix each morning, though she'd be willing, though reluctant, to live with grocery store coffee at $9/# roasted.

The numbers:
My coffee: $7 * 26 * 9 - 200 = $1438 cost for 12oz home roasted every other week for 9 years, less half the cost of the roaster.
My wife's coffee: $7 * 52 * 9 - 200 = $3076 cost for 12oz home roasted every week for 9 years, less half the cost of the roaster.

If I didn't roast:
My coffee: $16 * 26 * 9 = $3744 cost for 12oz specialty roasted every other week for 9 years.
My wife's coffee: $9 * 52 * 9 * 0.75 = $3159 cost for 12oz grocery store every week for 9 years.

Hers is pretty much a wash, I should be able to afford a $2k replacement for my Behmor.

For me it was never a money equation. I love to tinker and roasting/experimenting is simply a lot of fun. Overall, this hobby is cheaper than most.

I slowly transitioned from smaller air roasters -> Behmor -> TJ-067 over 5-7 years. Lots of fun.

You will save a fair amount of money. Good green runs 6-7/lb vs. 15-20 from my local roaster.

Lets see I drink 1lb/week x 52 weeks a year:
Green: 7 x 52 = 364
Roasted: 15 x 52 = 780

save ~416/yr == My total setup ~5k => break even approx 10yrs