Charlee loves romaine lettuce. She pretty much has what the guinea pigs have - which amongst a whole range of things includes a variety of 'gourmet' lettuces and endive (type of lettuce). She is not a big veggie eater and prefers to leave them and come back later. Not sure if this will all change when she gets her husbun though.
Iceberg lettuce is the one that is a no-no. It has very little nutritional value and is basically water - so often results in runny poops. I never feed this to either Charlee or the guinea pigs.
I am also with your husband though. The prepacked stuff is a lot more expensive (because you have to pay for packaging) and you can't always see the quality throughout the whole packet. Often the produce isn't as fresh as well. When I go to the fruit and veg markets to get the weeks produce, I get fresh veggies (and for cheap). Then when I get home, I wash and cut it up to fit into 2L plastic containers. When it comes time for their veggies, I pull out a couple of containers and they are all ready to go. Takes a bit more effort, but you save yourself money, you get quality veggies and all the veggies are pre-prepared and ready to go.
Saying all of that, I often get told off for spending too much on veggies. I have to stick to a budget of no more than $20!!