Hi Parisa,
1) Some wholesalers may do this (indeed Sarah's co-op have enquired with a couple of suppliers whose prices were more than what they could buy at the local supermarket), but the majority offer significantly cheaper prices (we did a comparison and found co-ops save members up to 80% in NZ), especially since they can supply in bulk quantities instead of individually packaged items.
2) Cobuy does not facilitate the delivery, just the order process.
3) See above.

We have updated our entry with a business plan. In which we have an area for partners.

We would love to hear from peeps if anyone has a suggestion for a partner.

We have been thinking about it in terms of:

TECHNICAL/SOFTWARE PARTNERS

GOVERNMENT/NON-PROFIT PARTNERS
INFRASTRUCTURE PARTNERS

Out of OpenIdeo we are totally going to talk to Chad Knutsen from this entry about collaborating the https://challenges.openideo.com/challenge/food-waste/ideas/our-sustainable-dehydration-turns-post-harvest-food-waste-into-profits-for-producers-and-nutrition-for-people

Haven't yet - its on the backlog ;)

Any other suggestions welcome!

Great question. We are aware that there are several pieces of software in this space. I'd say we are the new kid on the block who are looking to do a mobile-first experience and that building software from scratch on new software paradigms and frameworks trumps old software any day. In other words "ones already existing for a long time" does not mean they're better - and can mean they're worse.

I do think our vision may differ - we don't want to just solve the admin problem of buying groups, we want to make the supply chain open and accessible. Getting there starts with co-ordinating  buying power.

Thanks for the question - that one has popped up before and I am still not sure if my answer is satisfactory. I will think about it some more.