Actually, I am mostly concerned with the way the price scales, especially how drastic a -1 to cost can affect the price at high levels. Let me write down my concern in a mathematical fashion -- its hard to clearly express is only words.
1) For a normal weapon, the base cost equals to 2000 times the square of the total price modifier. i.e. P(x) = 2000 x X^2
2) Let us say that the weapon imposes a -Y peanlity to hit and to damage. i.e. For a -1 flaming weapon, Y will equal to 1.
3) Define Z to be the base cost of the masterwork weapon.
4) In your method, the bse cost of a weapon with negative enhancement will equal:
Q(X, Y) = 2000 x (X - Y)^2; Y = 0, 1, 2, ... , X-1 (since you retain the base +1 enhancement)
Q(X, Y) = 2000 x (X^2 + Y^2 -2XY)
at the high end, when Y = X - 1; the cost is a constant of:
Q(X, X-1) = 2000 x (X - X + 1)^2 = 2000 gp -- a constant
So in your method:
+1 weapon costs: Z +2000 x (1)^2 = (2000 + Z) gp;
-1 flaming weapon costs: Z +2000 x (2 -1)^2 = (2000 + Z) gp;
-9 Dancing Vorpal weapon costs Z +2000 x (10-9)^2 = (2000 + Z) gp;
The cost does not scale with the vast increase in bonuses. However, in specific conditions, a special weapon, even with -9 penalty, will be far better than a straight +1 weapon. In all other cases, you can just switch to another weapon, and thus avoid the penalty.Therefore, the penalty cannot be seen as balancing the bonus, since the penalty can be easily sidestepped (or bypassd entirely with magic).
In D&D, it is always assumed that the characters will seek to maximize to use of their strengths, and minimize the use of their weaknesses. In this particular case, if the -9 Dancing Vorpal weapon carries a
curse, so that you
must use that weapon and that weapon only (similar to the
-2 cursed longsword in the DMG), I would say that the 2000 gp base price is correct. However, it is not the case here.
Also, another small drawback of our method is that you cannot construct +0 weapons (with enhancements, of course), unless you make a special rule for them.
5) Therefore, in my post I proposed that the penality be 'added' as a negative cost, instead of directly subtracted to the bonus:
R(X, Y) = 2000 x X^2 - B x Y^2; B = 200 gp, Y is the penality to attack rolls and to damage, Y = 0, 1, 2, 3, ... X.
Actually, the number B = 200 gp is just an arbitary guess --
Coredump said:
But these are not skills, and the DMG shows us that pluses to hit are worth a *lot*, so then shouldn't penalties to hit be worth a lot?
-- is a convincing argument for a greater number, perhaps B = 1000 gp instead. I do not believe that it is worth the full 2000 gp (see above), but 1000 gp may be a better number than 200 gp. The best, precise value must be discovered by playtesting. I will use B = 1000 gp in the calculations below.
In this method:
at the high end, R(X, X) = 2000 x X^2 - 1000 x (X)^2 = 1000 X^2; i.e. half price of a non-cursed item, which still scales with the square total enhancement.
More importantly, a minor -1 or -2 penality to a +10 weapon will affect the price of the weapon minutely (note, a weapon with -1 penalty is a +0 weapon):
R(10, 0) - R(10, 3) = 1000 x (3 x 3) = 9000; compaire to
Q(10, 0) - Q(10, 2) = 2000 x [ 10^2 - (10 - 2)^2 ] = 72000 gp
+1 weapon costs: Z +2000 x (1)^2= (2000 + Z) gp;
-1 flaming weapon costs: Z +2000 x (2)^2 -1000 x (2)^2 = (2000 + Z) gp;
-9 Dancing Vorpal weapon costs Z +2000 x (10)^2 -1000 x (10)^2= (100000 + Z) gp;
At the low end, things are not much different, but this second method can more easily prevent high-end abuse.
As with all things, all of the above are my opinions only. Take what you can use, and feel free to disregard the rest. Either way, after you introduce the possibility to your players, I would like to hear how it works out in your game. The important thing, of course, to have fun. So... happy gameing!
