Look at it this way... you can hatch 10 eggs in a 20 egg incubator, but you can't hatch 20 eggs in a 10 egg incubator. In this case, bigger is always better. If you can afford a Brinsea, go for it... it's like the Cadillac of desktop incubators. While they're nice, most people can/and do just fine with less expensive incubators. You can find incubators for $200 (or less) that can hold up to 41 eggs and give great hatch rates. I was torn between the Hovabator 1588 and the IncuView from Incubator Warehouse. The IV only holds up to 27 eggs, but what sold me was the plastic construction, which is easier to clean and keep sterile as opposed to styrofoam. Building your own incubator out of an ice chest, old mini fridge, etc., is another option if you're even remotely mechanically inclined. These can save you a little money over pre-built units, but can be a little more fidgety.
Runs don't have to be built like Fort Knox to be safe. If hawks are a problem, nylon aviary netting will suffice, and it's not nearly as expensive as wiring or building a large roof. I don't even have wire buried in the ground around my pens/coops. I've been using Solar Nite Eyes since I got my first chickens, and nothing has attempted to get into the runs/coops. Mounting 4 of them in the corners of the runs and coops is lot faster and easier than burying wire...