Diy, where to shop for this terrarium centerpiece?

Your idea seems to combine two ideas- a geometric terrarium vase (which are almost always shapes made from triangles) and a cylinder pan vase with the gold rim like a terrarium. You could paint the gold edge or find the fake lead trim that they use in stained glass that is gold.

cylinder pan vase

http://store.wholesaleglassvasesint.com/index.php/cylinder-glass-vases.html?cat=60

https://www.amazon.com/Clear-Large-Cylinder-Candle-Holder/dp/B00A9JU0CK/ref=sr_1_5?s=home-garden&ie=UTF8&qid=1530889685&sr=1-5&keywords=cylinder+pan+vase

LED candles

https://www.amazon.com/Flameless-Waterproof-POLIYU-Operated-Seasonal/dp/B075FLQ9XT/ref=pd_sim_201_2?_encoding=UTF8&pd_rd_i=B075FLQ9XT&pd_rd_r=f4d99994-812e-11e8-9496-9bd53828afac&pd_rd_w=oPaQX&pd_rd_wg=2Q6Uk&pf_rd_i=desktop-dp-sims&pf_rd_m=ATVPDKIKX0DER&pf_rd_p=7967298517161621930&pf_rd_r=YZACAWR2R8AP2FRC1YGX&pf_rd_s=desktop-dp-sims&pf_rd_t=40701&psc=1&refRID=YZACAWR2R8AP2FRC1YGX

https://www.hobbylobby.com/Home-Decor-Frames/Candles-Fragrance/Flameless-LED-Candles/c/3-111-1065?q=%3Arelevance%3AcolorFamily%3ARed&text=

Hi Ashley! I love this DIY centerpiece inspiration! Welcome to WeddingWire and congrats on your engagement!

Amazon, local craft stores, the dollar store, and even the craft section of some Walmarts and Targets might have some low-cost vases and these candles you are looking for!

Are you doing natural or artificial florals in this centerpiece?

If you have any other questions throughout your wedding planning process, please don't hesitate to connect or post another discussion.

I will checkout my local dollar stores this weekend! The sheer circumference is the worry here. I have been fiddling around with the idea of using strips of craft plastic to form the "terrarium" part. It has been ages since I've worked with acetate so I am a bit on the fence.

As for flowers, they are all paper and artificial.

Thank you everyone for all the advice so far, it is really helping my brain get unstuck from this conundrum. Maybe I could get rid of the "glass" all together and create some other form of dynamic blocking?