It all depends what you will use it for and what quality glass you want to look through...
Yes, there is a big price jump from about $500 to $1300 (PST 1-4 and razor hd 1-6). Have you ever looked through razor hd 1-6? The glass is the same quality as other famous brands selling over $2000. On 1-6, the picture is totally stunning. PST 1-4, the glass is average but okay. I feel that it is easier and faster to find your hold on 1-6 when shooting 400-500 yards in the match than doing the same with 1-4. The reticle is perfect on 1-6. It is not too busy and it has just all the right things you need. Illumination dot and its settings are great and help a lot during the matches. Even though people with 1-4 are trying to downplay 6X, but 6X is much better than 4x especially on this scope. the exit pupil is very large at 6x (versus other scopes) and clarity is amazing at such magnification.
Besides matches, I also wanted to use this scope for hunting. I only shot through it at hogs at no more than 300 yards and I am happy with this scope performance in hunting too.
If you were to get a cheaper 1-4 scope now, but then later you might regret that you did not pull up all the way to 1-6. I see a bunch of folks trying to sell their 1-4s and upgrade. Don't be one of those later on. and just buy 1-6 now. Ebay authorized dealers have some great offers. That's where I got mine from.