My husband and I have seven kids. I think it's easy for us, because we do trust God, for everything, and He does provide. The thing about having more children is that it's slow and one at a time. SO it's not like taking in seven children, it's adding one beautiful personality at a time, plenty of time for adjustments both on time and finances. It helps that dh is the oldest of eight, so we had a wonderful MIL (who passed several years ago) who helped us with advice and tips on family, and he has lots of experience.
Dh works well, not just hard but with ethics and virtue, and is recognized for it. So he definitely makes enough to support us. Preparing meals we just double every recipe. We don't buy a lot of convenience food, first of all it's not convenient when you make it for ten people! Secondly, it's most chemicals and preservatives, and lastly it's much cheaper to use natural ingredients and make it from scratch. It takes a bit more time, but really not that much more. So that's how we afford groceries. We do buy a lot at Sam's Club, esp now that they carry a lot of organic foods. We buy a lot from the local farmers market, and grow some of our own. Clothes are similar, we don't buy a lot of high end brands, but some, and we buy quality clothing because it's worth the investment to have something that won't wear out easily or hold stains.
As for attention, since my life is my kids, it's pretty easy. It helps a lot more that we homeschool, so we aren't trying to fit a bunch of family time in between 3pm and 9pm, and on the weekends. The difference between having two kids and seven is that with two kids, you're splitting your time up. WIth a large family, you spend a lot more time as a group, rather than a lot of individual time. Dh and I take turns having 'dates' with the kids, where we'll take one for ice cream, or dh will take one to work for lunch. They are all precious in our sight, and we're thankful for each and every individual who makes up our family.