Are lower rquirement weapons considerably more expensive?

How would a r10 crennelated sword be against a r7 crennelated sword with the same mods?

I'm going to give you the short answer

A R7 means only 7 in sword and if this said sword, is same as a R10 ie mods and damage the R7 sword will be very expensive and very rare.

Hope that answers your Q

The R7 would cost buttloads of ectos. The R10 would be a few platinum.

R7 does same damage as R10 assuming you're not bad at warrior and run 12+ weapon (ideally 14 with 13 str).

Besides, the staggering amount of people that don't customize R7s makes me cry inside. You might as well customize a max white to get +20% unconditional rather than +15% conditional.

I can understand the "oooh that looks rare" logic, which to some justifies the high prices

But IMO, you're not going to run a build with R7-8 sword/axe/hammer(lol)/etc, because you will do considerably less damage from the skills (or heals), sure you could do that, but why?.
You could think that "well, I'm going to be able to use it at max capacity from an earlier level, since it requires less points into X attribute," but you wont be below 20 for too long, and in most cases it's not too difficult to get the extra 15(?) attribute points.

But hey what do I know... NOTHING, that's what.

A low-req weapon with max stats is not actually any better than a r9/r10 weapon, but it is significantly rarer. Hence they sell for much, much more.

I collect low requirement items. They are purely Epeen (not that I have ever bragged about them apart to other collectors maybe).

There is absollutely no difference in damage between a req. 7 Crystaline 15-22 15^50 Sword and a req. 11 15-22 Elemental sword with a 15^50 inscription. The rarity of the item is the only reason for the price difference between 1K and insane amounts of Ectos/Armbraces.

Its the same with bikes you would use in real life to travel 3 miles to work. You can have the 100$ cheap Walmart bike which works fine on roads or a 5000$ professional racing bike... both will get you to work, both do the same thing (on the short 3 Mile ride you would be needing it for), but the 4900$ difference is purely peen if you dont use the racing bike professionally.

Yep, I'm that point where I'm just rich enough to buy the high end weapon but not so rich that I'll customize it. All of my melee toons are running around with fairly cheap weapons that I was able to in good customized without losing sleep over it.

In what possible way does it "ruin" the weapon. The weapon still works perfectly fine. It only affects it's possible resale value, which is basically of no importance to you once you have enough gold. I mean, why would you ever need to sell it? There is no point to simply hoarding huge amounts of gold.
Not customizing it only makes it a free gift for an account hacker.

What about for ppl running a /W secondary. Would there be builds that use a lower number in sword and therefore, require a sword like this, making it cost more?

Basically, everytime something goes down 1 level in requirement it gets at least 8 times more expensive xP

No. If you're using a sword and not a Warrior primary, you're running a bad build. If you're a Warrior and not running 14 Swordsmanship, you're also running a bad build. If you plan to use a weapon as a primary source of damage, you're going to be pumping as many points into it as you can.