Actually both are pretty much equal or similar in price.
Foam is expensive, same as heatgun, then glue - super glue or contact cement, then something to seal it. Plastidip isn't cheap. Xacto blade and blades for it or sharpener. Etc.
Few cans or resin, fiberglass, some body filler. Cardstock and something to cut. Sandpaper.
At the end both come out pretty similar, just with foam you need to spend more money at the beginning at once, whereas with pepakura you can buy stuff with bigger breaks (at first you need to cut out and glue your parts together, and only after you have done these you can cover it with resin, after that add fiberglass inside, etc.)
I would probably say foam is the cheaper and arguably easier option, foam isnt that expensive and you only require some form of sealant (PVA works well) and then paints, while I would say that Fiber glassing has a better finish at the end result? Downside with foam is that you need a few more tools. Knives, heatgun, hot glue ect but then again that isnt that pricey either.
Someone with more experience could probably correct me, but thats my thoughts anyway, I have only ever worked with foam.
In all honesty both can cost a pretty penny. I primarily work with foam so, I can't say much for cardstock & fiberglass. It's to do your homework and research to get the best prices for your materials and tools.
With the foam, contact cement, super glue, knife, replacement blades, ruler, cutting mat, cardstock, sand paper, heat gun and rotary tool, costs were already over $150 Canadian. On top of that I purchased both Modpodge and Plastidip for sealing and then there is paints.
Don't let my list scare you. All this stuff doesn't need to be bought all at once. Especially if your budget is tight. Buy things as you need them. Paints for example. Save those for last since you would still be in the build stage.
Hope this helps a bit.
I have done my armor with pepakura, so resin, fiberglass, body filler all the way, but I also used EVA foam for mainly undersuit parts and lately I'm using more EVA foam for adding raised areas and details on the armor, so I could say I work with both.
Lately I was buying bit of 2mm and 5mm EVA foam and I was shocked how expensive it was. v_v
That's why working with both and comparing the prices overall - they are pretty much the same when it comes to the prices. :/ (and it made me laugh so hard at some people shouting "foam method is cheaper!" because I realized it's a myth and the only difference is that the pepakura can usually take bit more time from start to finish)
Don't bother w/ a cost analysis........both methods are going to cost you....whatever each is per suit...... so the best thing to base you decision on availability of material (some material isn't readily available all over the world) , time allotment (Pep takes longer to produce pieces...so how much time can you devote?), durability ( Pep is stronger but if you drop a foam piece, it won't break or chip like foam), weight (Foam is much lighter but you will start to heat up in a foam build unless you live in a cold temperate area) and lastly, which one you prefer using......now everyone has their own opinion on which is better but that is something you have to decide by yourself.
For a rough estimate of my first foam build's cost, someone can jump in with their pep build to help out Ethan
My suit is Halo 3 ODST built modified to be like the Halo 3 Landfall suits. I'm 5'9", 170lbs and hockey player build. All prices are in Canadian Dollars and everything is assuming zero tools are had at the start of the project.
3'x4' cutting mat ~$30
Heat gun - $25
Disposable 10mm snap off blades (10) - $4
Hot glue gun - $15
High temperature hot glue - $10
Gorilla Glue - $8
32sqft of 1/4" EVA - $28
Plasti-Dip Spray Can(2) - $42
Spray paint and primer (6)- $40
Acrylic paints (various) - $10
Lexan - $20
1" nylon webbing (6m) - $12
1" Velcro strips - $8
Buckles and fasteners - $20
Marine vinyl - $15
12V Cooling fan - $4
Battery pack - $2
Boots - $60
Pants - $45
Turtleneck - $10
Balaclava - $6
Aker Voice Amp - $60 + shipping
So rounding it up if I was to go from absolutely nothing to wearing my costume $474. This is an estimate, some numbers would be higher, some would be way lower and some of the items were already in my possession at the start of the build.