I think that if you have the resources for another rabbit, it really does benefit them to have a partner. In my mind, these are the resources:
Space: Two bunnies of course means more space, but you also have to take into account that they will need separate living areas during the bonding process. X-pens can solve this problem pretty nicely. Separate litter boxes and feeding areas will also be needed for bonding.
Time: Bonding requires lots of time… your time, specifically
Facilitating the bonding process means that you will have to supervise lots of “dates,” which will be short at first, but will eventually require a couple hours of your attention. These dates can go on for months before they are ready to live together. If you adopt a bunny that is not litter-trained, you will also have to take training time into account.
Money: I’m not sure if your little guy is neutered, but if you decided to get another bunny, having both of them fixed is essential. (Even if you just have one bunny, it is very important.) The surgery can run from $100-300 for each rabbit. With a new addition you will also be doubling feed, hay, and veggie purchases, and more vet checkups as well.
I sure there are more things to take into account, but those are the issues that come to mind. Rabbits don’t mind alone time, but I think it is very enriching for any social animal to have company.