I think the stump grinder would be the easiest attachment to pay for by hiring out.Obviously Tim is running a business but I've found you can do similar with just a Saturday morning or two each week. I usually try to take two or three small jobs each month to pay for my toys. I'm not trying to make a living with my tractor but I like recovering the cost of the equipment. I posted here awhile back about a tiller that paid for itself a couple times over just by doing a few gardens each spring when I had it hooked up anyway. I think a guy could recover the cost of that stump grinder in a year or two easily.
Insurance becomes a factor here so I'd be in touch with your agent before taking any jobs for people you don't know and trust.
Everyone has stumps which need to be ground.
You can work year-round too.
Most attachments are seasonal.
The 1P24 is selling very well!