Unfortunately an offset for that price is not going to be of great quality. This is made by charbroil and I believe they are made in China now. I would surmise that the emphasis on quality has been lost, but that's my personal opinion.
Most well built offsets will be larger and will probably use reverse-flow in an effort to keep the cooking chamber more evenly heated and a more uniform application of smoke.
Check Craig's List for used offsets, that way you will not feel disappointed because of what you spent on a cheap offset. However some of these can be modified to perform very well if you have the time and ability to do the work on the smoker.
Bottom line is search and look at what a good horizontal smoker is priced at, then compare it to the Charbroil OK Joe. You will see that you get what you pay for.
Try building a UDS if the budget and you space is limited. Surprisingly enough these produce some great BBQ food items.
Humphrey's DownEast Beast W/BBQ Guru