So if you're like me you'll dislike the very silly idea that it takes as much effort to figure out how to make a road an extremely complex as it does a highly complex mechanical system and... togas. Fancy tribalwear.

Thankfully we can fix this! And whilst I could provide a patch I'd rather let people set the values themselves, plus this knowledge carries over to any mod you'd like to "Harmonise" in terms of research cost.

Head to ...\steamapps\workshop\content\294100\2787850474\1.4\Defs\ResearchProjectDefs and open up these three files in a text editor of your choice, although notepad will do.
ResearchProjects_CentralRepublic.XML
ResearchProjects_EasternRepublic.XML
ResearchProjects_WesternRepublic.XML

You'll see a description of each research item and its cost. We're looking at these 'chunks' of code. I'll put a couple of comments in that are ///trailing triple slashes.

<ResearchProjectDef>
<defName>VFEC_Togas</defName> ///This is what we're editing, read this bit.
<label>togas</label>
<description>Craft togas, everyday wear of the citizens of the republic.</description>
<baseCost>1200</baseCost> ///This is the only thing we're actively editing!
<techLevel>Neolithic</techLevel>
<researchViewX>10.00</researchViewX> <!--Increased by 1.00 each time-->
<researchViewY>00.00</researchViewY> <!--Increased by 0.70 each time-->
<tab>VanillaExpanded</tab>
<tags>

I set the values as follows since they're a (very) rough logical question of "How much effort does it take to make this thing based on its complexity in terms of production chain or scientific breakthrough?

Crafting Bench = 100
Beacons = 100 (Seriously?! It's a pile of ♥♥♥♥♥♥♥ wood!)
Drama & Comedy = 200
Togas = 400
Mosaics = 400
Cement Making = 400 (Could probably bump it to 600 though)
Scorpion = 400
Bronze Working = 600
Legionary Armaments = 600
Legionary Armor = 600
Centurion Armor = 600
Heavy Shield making = 600 (Rename to "Heavy Shields"?)
Thermaebath = 600
Wood fired crematorium = 600
Temperature Control = 800
Meat Drying = 800
Road Building = 800
Tyrian Production = 800

Now this is by no means a "Best research cost list" but just my subjective best guess at good numbers. This is why I'm giving people the means to set their own costs instead.