At that price, you are probably looking at 2D sonar, black and white. For a bit more, you can move to color with DI. The difference between the two is like the difference between the inside of a giant cave with only a candle and being outdoors on a bright sunny day. With 2D sonar you will see blobs. Blobs might be a brushpile, a big ball of bait, a school of crappie, or even just bubbles. With DI, that blob will be something you can probably identify....if it's a tree/brushpile, you can see every branch and even see fish holding on branches. If it's a ball of baitfish or a school of crappie or even a mixture of the two, you will be able to see that also. In my opinion, it would be worth it to save for a while and get the best unit you can. Use the handheld GPS to mark spots where you catch fish, or feel brush when you are fishing.