Hi Emma
Firstly you are being a really good bunny mum...you are trying to find out information and you are looking after your little critters really well.
It can be a daunting task when you find out that there is so much to find out! But you are in the right place and friendly advice is just a mouse click away.
Pet stores really receive very little from the sale of the small animals and are interested of course in selling the pet. They seldom give advice following the sale and VERY often have no idea about sexing bunnies.
A pet shop is not a good place to get your pet, however you have rescued a lovely little lion head cross and he/she is very lucky (literally! lol) to be with you.
By now I suppose you have seperated the two buns. If Benjamin manages to impregnate your little Lucky there could be serious problems as Benjamin is literally twice the size and this could make a very hard journey for Lucky.
If they are boys then of course they MUST be neutered, BOTH of them as their hormones could easily go from sweet and cuddly to testicle ripping off action, and I am not kidding here. Bunnies can seriously harm each other when territory is being fought over.
You will need another cage for Lucky.
Just carry on giving them good food, as much attention as you can and you will be fine for now.
I will try find out the costs of neutering your boys for you and get back to you.
Just ring around the vets too (rabbit savvy ones) and see what they have to say.
Here are some links that may help:
http://rabbitsonline.net/view_topic.php?id=11506&forum_id=1