I agree with
@axcxnj ....you get what you pay for... That said, some of Dicks' inventory is decent. Just like bikes, there are brands that are junk, basic, upscale, advanced. For a good mid-priced decent quality boat, I'd go for Perception. Other solid brands include Dagger, Old Town, Wilderness Systems. You can find several of these brands at stores like REI and Pelican Ski. I am not crazy about Pelican brand kayaks (not associated with Pelican Ski), Future Beach, Sun Dolphin.
As for type of boats, like bikes, it depends on what you plan to use them for....flatwater: sit inside. Whitewater: sit on top. Beach: Sit on top.
A sit-inside will typically track better on flat water. Sit on tops, on the other hand, are better for beaches and/or rougher rivers where likelihood of tipping and/or getting lots of water in the boat is greater. The reason they require more effort to paddle than sit inside kayaks is that the drain holes (there are typically 6 per boat) can create drag.
We have 4 sit-insides in our family, all Perception, ranging from 9.5 to 13 fit. They have served us very well.
I also have a sit-on-top Liquid Logic for running whitewater up to Class 3. Have to say, running a river like the Lehigh in one of these things is a blast. Kinda like a liquid rock garden: