I agree with everyone here with saying support is the biggest thing to look at when getting into racing. I am new like yourself, and I was more or less forced into going with OTK. I chose an FA Kart because I liked the colors the best. My decision factor came down to my local track that I will race at probably 97% of the time, only stocks and/or carries OTK. I would rather not have a race or race weekend end, because my shop can not get the part because they dont support the brand. If it is something like the part is an unusual break they don’t normally stock, or they are just out of stock, well that is my fault for not being prepared.
I would say if you can find a low time used chassis you will always come out ahead. I got an 2012 FA chassis that had 5-6 hours on it for 2000 used, not a scratch on the underneath of the chassis. Deals are out there, may take more time to source them out, but they are out there. Also go to a race day, you would be surprised some of the absolute steals you will find on a race day.