Ollie runs a small convenience store. His premises need some emergency repair work after some severe storms, and he hires Patrick to perform it; they do not agree a price for the work, but it was taken for granted between them that the work was to be paid for at ordinary rates.
After a few weeks, they discuss payment; Patrick then proposes to forgo payment so long as Ollie, in return, supplies him with a set list of groceries (ordinary price roughly €30) every week for six months. Ollie agrees. However, before this can happen, Patrick changes his mind and demands €2,000, which is his usual rate for the sort of repair work he did. Advise Ollie.