These have come on the market lately, and you would probably need a new one since I haven't seen any used ones.
For $600 you can get a used LOMO, Intes Micro, or Orion Argonaut Russian scope that is in a different league altogether. My Russian LOMO 150 OTA was $500 and came with a killer 40mm 10x40 right angle finder that is the sharpest I have ever seen. It easily outperforms my 50mm right angle Stellarvue F50 finder.
That gives you no in depth info on the Orion, but it is Chinese manufacture and they are not there yet in competing against the Russians in Mak scopes. There are plenty of used Russian Maks for sale out there, and your smart money will be grabbing those while they are available and very reasonably priced.
If you buy a used Russian scope, you can get your money back when you sell it. That isn't going to happen with a new Chinese Mak, and you are far more likely to want to get rid of the Chinese Mak for any optical quality issues. My Russian Mak is not only built like a tank with killer 1/8 wave optics, the tolerances are very tight with zero image shift when focusing, etc.
If you have a focusing issue with a used Russian Mak or American SCT, a Borg helical or JMI Crayford made for that purpose fixes the problem. If I wanted a Chinese scope, I think I would be looking at a new Celestron 6" SCT. Reports are very good on it, and it's a much better deal with the included mount in the scope package. The f/10 speed is better for all around use. You will not be stuck with an orphan later on if you get the Celestron SCT.