I think that the one listed is either a Compact-I or a Compact Jr. Be sure of what you are looking at. The II will usually have more cabinets, a slightly smaller bed and more interior features and appliances and often, a bathroom.
But adding
brakes (really not needed anyway) is usualy an after market item as it requires a new
axle. If you want it to fit in a garage be sure to measure it first.
That said, $3000 seems like a good price or a decent stock unit without a lot of extra features or updating like a
refrigerator, hot water, a pressure water system, or a
furnace.