There's got to be a way to balance the slot machine, eventually you'll get it I'm sure. But right now it's actually pretty terrible.
Sinking about 4k gold in, with no payout = lame, considering the chances of getting an R1 item are the same as an R5.
It kind of sucks because right now nobody really buys things from the vendor house (due to already having, iirc).
Again, I'm sure it will get balanced eventually. If the goal of the slot machine is to just be a money-pit, fine. But I'd even prefer it if you scrapped the money payout completely (since it's balls) and replaced it with something like a randomized R1 item. Then at least there's some incentive to sink the money in.
edit: The enchanter is showing what looks like the results of a dice roll. ex; "25 - the enchanment failed"