Pretty telling Jones will have a significant role in this offense having not played last night. This reeks of a RBBC on a bad team. One thing is for certain, Alf has been severely overdrafted.
I think his role won't be much different than Helu's role was last year. While it's significant, it's not worth the going rate IMO.
Almost every backfield is a RBBC to some extent. Helu was seeing an average of 40% of offensive snaps over the last two years which likely correlates with WAS being terrible. In games where WAS lost, it was common to see Helu finish with 4-6 receptions. I also think Helu is chronically underrated; he's more than just a 3rd-down/COP back.
I think the difference between Jones and Helu is really just timing. It's one think to try and unseat Morris after his outstanding rookie season but after several years of decreased effectiveness I don't think WAS is as averse to letting someone else eat into his early down work.
I disagree with your last statement, in most leagues Jones is still pretty much free.