I don't believe the rules really cover that in any great detail.
In any case, I imagine such an item would cost the same as it's magical equivalent, would work in an antimagic zone, and require a power source.
Technology does what technology does; magic does what magic does. It's not as simple as "substituting tech for magic for the same effect" or vice versa. This is spelled out fairly explicitly in Crafting High-Tech Items
Items with both magical and technological components, such as the null blade, use a special crafting process. The creator must first succeed at a skill check at the listed DC for crafting the technological portion of the item, and then must succeed at a check based on the item's caster level for crafting the magical portion. Any spell or level-based prerequisites not met increase this crafting DC, as described for magic item creation. The skill used for each check is based on the item creation feats required by the item. Failure on either check ruins the item. Use the item's listed price as normal for determining crafting time, and the item's cost for raw materials. If the creator has feats or abilities that accelerate item creation, only the least favorable bonus applies. In other words, to create a hybrid item faster, the creator needs to be able to create both magical and technological items faster.
It is also possible to enhance high-tech armor and high-tech weaponry with armor special abilities or weapon special abilities, including magical enhancement bonuses. One could build a +2 laser rifle, a +4 dancing humanoid bane chainsaw, or a +1 ghost touch spacesuit. In theory, a magic item creator could even infuse a technological item with magical intelligence. To create a magical high-tech item like this, one must first secure the high-tech item itself, either via purchase, discovery, or crafting. All high-tech weapons and armor are considered masterwork for the purposes of adding magical enhancements to them (though they do not gain the other typical benefits for masterwork items). At the GM's discretion, some magical special abilities might simply not be appropriate for application to certain technological items. When a character crafts an existing technological item into a magic item in this manner, he does not need to meet the base item's crafting requirements—a wizard with Craft Magic Arms and Armor can create a +1 arc pistol from a normal arc pistol without having Craft Technological Arms and Armor and without having access to a military laboratory. In a situation where a character wishes to craft the entire item from scratch, the nonmagical technological item must be fully crafted and completed before work on magically enhancing it can begin.
Also, this is emphasized in the introduction to technological equipment: "Many technological items replicate specific spells or magical effects. However, they do not use magic in any way, and thus function normally in areas of antimagic or primal magic, and are otherwise unaffected by any effects that target or affect magic items."
As far as using a "tech" weapon, you have two choices: use an existing technological weapon (chainsaw, laser torch, monowhip, or stun baton) or a weapon made of a skymetal. Adding "plusses" or weapon abilities would then require it becoming a hybrid item, as described above, because technology has no equivalent of "+5 bane speed."
a tech only scimitar is a scimitar with no enhancements. there is no Tech enhancement variant, tech weapons are instead insanely powerful, while some armors count as having an enhancement bonus or do really cool and unique things.
Technically there is an item that clips on to a melee weapon and gives it the damage of a higher size...
still not an enhancement bonus or breaks DR~/anything
From the PRD (and I think I heard page 17 of the book)It is also possible to enhance high-tech armor and high-tech weaponry with armor special abilities or weapon special abilities, including magical enhancement bonuses. One could build a +2 laser rifle, a +4 dancing humanoid bane chainsaw, or a +1 ghost touch spacesuit. In theory, a magic item creator could even infuse a technological item with magical intelligence. To create a magical high-tech item like this, one must first secure the high-tech item itself, either via purchase, discovery, or crafting. All high-tech weapons and armor are considered masterwork for the purposes of adding magical enhancements to them (though they do not gain the other typical benefits for masterwork items).Magic and tech work simultaneously, and the appropriate parts shut off in the appropriate dead zones/circumstances.
+4 dancing chainsaw… nuff said
Where are the stats on the Skymetals? I've seen the stats of a few, but I don't think I've seen them all in one place. Heck, I'm not so sure that I've even seen them all in different places.
+4 dancing chainsaw… nuff said
+3 impact keen adamantine chainsaw... 4d6/15-20 two-handed weapon that ignores hardness of less than 20. :-D
