Space for 2 bunnies

So I currently only have one bunny. I just recently bought a cage for her that is 3x4 foot. At my local pet store, there is this bunny (same kind: lop but white and tan instead of white and black like my bunny) and she is grown now. She has been there too long, nobody has bought her so they reduced the price. It breaks my heart to see her, week after week, surrounded by little bunnies while she still hasn't found a home.. How much cage space would I need if I decided to buy her? I assume the new cage I have isn't big enough for the both of them. But I still have the old cage I could put the new bunny in for now. What do you suggest for space for 2 bunnies?

Is your current bunny spayed? I imagine the one at the pet store is not spayed either?

Are you planning on keeping the new one in the old cage? What size is it?

I assume you are planning on bonding them in neutral space once they are both spayed. If they bond successfully and you plan to give them plenty of time outside the cage every day, the 12 square feet could work. Otherwise, you could have an exercise pen serve as additional permanent space around the cage.

Remember there are no guarantees with bonding. Be sure you are prepared to house them separately always if they refuse to bond.

BTW, I understand your wanting to "rescue" her from her situation. There is a rabbit at our local pet store from a shelter. They have him in one of those plexiglass enclosures they usually use for guinea pigs. It has a solid lid too with too few air holes. :bigtears:

It's a full grown New Zealand and they had the water bottle spout a mere 2" from the floor. I pointed it out and they could not adjust it so they got a smaller water bottle. :foreheadsmack:

They had the crappy mixed pellets for him & a miniature hay wheel (at least they had hay).
The plastic hidey house was too small for him to fit through the opening.

How old is your bunny? You need to spay her before introducing another rabbit, to avoid fights but also babies (you really can't trust sexing done by petshops). You need to be aware that female rabbits need to be spayed around 8-10 months for health reasons, so even if you end up with 2 females you'll need to pay for two spays (do you have enough money for that? assuming your in the US, it might cost around 400 $).
Also, will you be able to keep the rabbits separated if they end up not getting along? Two females can be done, but it isn't an ideal pairing.
How much time outside of her cage does your rabbit have? My pair live in a cage which is roughly the same size than yours but my rabbits have 16 hours outside of their cage everyday (they are only confined when I'm sleeping). I'm not really partial to keeping a pair in a cage for most of the day because the rabbits can't isolate themselves if they want to (it really depends on the rabbits' personnality - Aki likes to have her "alone time" during the day) and until the pairing is really stable it bothers me to keep a pair in a confined place because if any fighting occurs, the weak party won't be able to flee...
So I guess it all depends on your rabbit, your general situation and how much you are willing to "sacrifice" (money and potential time) for the rabbit.
Nevertheless, I feel like I have to point out that playing on the feelings of people is the way petshops make money - it's not the best place to get a bunny as it encourages a pretty nasty industry (I don't know where you live, but in France most petshop's money go straight into the eastern europe countries and partially funds 'business' like forced prostitution, I'm not even talking about the conditions in which the animals used for reproductive purpose are kept or the fact that most of the animals brought to petshops don't survive the trip). If you want a second bunny and wish to save one, I would rather take a nice neutered male bunny from a rescue.
If you decide to take the petshop bunny, don't forget to quarantine - things like mange run rampant in petshops. Bring her to the vet quickly to assess her general state and make sure she is indeed female. Also, you'll have to introduce the vegetables very slowly as most petshop rabbits don't have access to greens (their parents either) so their stomaches have trouble digesting natural food (the multiplication of petshop bunnies has caused this legend that young rabbits can't digest vegetables, which is of course not true if the rabbits and their mother were fed as they should be).

I second the recommendation to adopt a bunny from a shelter if you can. Shelter bunnies are vetted, neutered and because so many are looking for homes the adoption fees tend to be cheap (less than $40 USD).

If that's not possible and you decide to buy the pet shop bunny, I'd ask the shop if they'll give you a 48 hour health guarantee so you can take it to a vet and make sure it's not suffering from any major health issues.

Re space, you can easily and cheaply build a pen around your cage with CC cubes. I build cages, ramps and pens with CC cubes. When I decided to adopt my second bunny I used CC cubes to build a temporary quarantine pen which was disinfected to become a "meet and greet" pen when it was time to bond them. It's very easy to make modifications like enlarging or shrinking cages and pens as needed. I tie the cubes together with zip ties. If your two bunnies don't get along you can build an enclosure for the new bunny. There are sites with plans to build CC cages online.

All I asked for was the space requirement for 2 bunnies lol I already know about all that other stuff if I choose to get the new bunny..