Case aka DirtSailor asked me to chime in on this so my 2 cents follows. I've always liked rotisserie anything so converted an old beer keg into a cooker that my original intent was to make 10 gallon batches of que sauce in. I hate Wal-Mart, however, during the pre-summer stocking of grills and such they had a rotisserie set-up for $25 which I bought. Got me a drill bit from Home Depot that would drill SS and 4 easy holes later had the brackets mounted. I found Weber charcoal baskets at HD as well to keep the coals off the rounded bottom...2 in a box for $15. Two bricks in the bottom of the keg and the baskets fit perfectly, allowing me to use both or only one depending on the cook. I'll eventually (?) get me a spinner that can handle a turkey with a more powerful motor. I understand they have battery operated ones for campers/hunters. With the Mini I don't think you would need the lid so perhaps this spinner would work on that as well. I, personally, would not or could not spend $150 on a add-on.....but, that's just me. Some pics..
spares with 2 baskets of coals
with 2 baskets & a apple chunk that ignited
with only one coal basket & a couple brix dropped in