You should probably open a gap then and farm some SP. In a good pt it is still quite fast even with Gap 5. When you are done with it and just decide to continue with lower gap for a while, your leveling speed will be really fast. And doing Gap
And while we were farming with our mates, we got like 3-5k SP each day. We did not use premium or other silk items btw. So, not really a big deal to get a level.60 farmed character sro gold. We did that for around 2 weeks and had 80k SP. But we agree on ISRO it's quite hard to farm SP on that way, as there are barely any pts in that level range and if there are pts, they are not really good.
So you should rather do this with some friends and you will be fine. And in higher levels in Silkroad, when the partys are getting even better due to better skills, equipment and so on. It should be even easier to farm SP. Killrate is increasing quite a lot with level.70/80+ on Roc Mountain, if you have a good spot with your pt.