I understand costs and competition prices, but honestly a free version for 2-3 people wouldn't be bad.

Similarly as saying that in a bigger team of 10 ppl one could implement it in house, in 2-3 there's no actual need (and setting up a reminder is trivial).

I'm also thinking to people that aren't working full-time (for whom a 3-day/weekly report would also be a nice feature).

As a small team (1 - 10), I would be willing to pay in the neighborhood of $5/user/month. Once we get up to $50/month, I'd like to see volume discounts.

I can't imagine I'd ever pay more than a $100/month for a team of any size, because at that price, I should probably just have an in-house dev develop a similar system.