Help please?

I'm using a Beheader myself right now. It's decently scrolled and I managed to get it much cheaper than it would have costed me to scroll. It comes down to that, do you plan on scrolling your sword? If that's the case, do a Devil's Sunrise. You can usually talk someone into dropping the price on a Beheader since it is slower, and the damage/second difference is roughly 7-8% lower than a Normal (6) speed weapon with the same stats. Unless you can get the same weapon for that much more money, it's not worth it. That's what I seem to come across. I got my Beheader (115/6 I believe) for 60M in Demethos compared to a Normal (6) speed weapon with the same stats for 100-150M.

In the long run, don't waste too much on scrolling a level 90/100 sword. Save up and start farming those Pieces of Time. A Reverse sword will always be better until the next set or a faster weapon at the same level is released (or Lunchboxes come back out). As for Stonetooth and Night Raven Wing, if you can manage the DEX requirement, you'll see a rise in damage. I'm DEXless, so it's near impossible without massive funding to reach 120 DEX to equip Stonetooth. With equips, I think I just broke 70 DEX. It's not easy, that's for sure.

It's best you just work cheap and aim for the Reverse sword.