Online Stores for TFs

Hasbropulse: https://hasbropulse.com/- Should be the go-to for mainline stuff, if you can get a preorder in soon enough
             https://eu.hasbropulse.com/

BBTS: https://www.bigbadtoystore.com/-BBTS is your friend but you'll be screwed from shipping internationally. Experience may vary. Shipping costs are dependent on customs for BBTS overseas.

TFSource: https://tfsource.com/-Extortionate prices on mainline. Use as a third back-up

Amiami: https://www.amiami.com/eng/- Japanese site, good for imports and some used stuff

Amazon Japan: https://www.amazon.co.jp/In-English/b?ie=UTF8&node=1094656

Mandarake: https://order.mandarake.co.jp/order/listPage/list?keyword=transformers&lang=en - Good for older/used stuff. Mind the shipping charge

Mandarake(ebay store): https://www.ebay.com/str/mandarake?mkevt=1&mkcid=1&mkrid=711-53200-19255-0&campid=5336728181&customid=&toolid=10001 -Good for used figures. Japanese collectors are autistic, so "damaged box" often means like, some microscopic dent.

A3U: https://www.agesthreeandup.com/-Good for leaves

Zavvi: https://www.zavvi.com/ - Good for bongs

EE: https://www.entertainmentearth.com/ - is also a store

ShowZ: https://showzstore.com/ - The premier place for the modern 3P collector

Special credit goes to Kreon-anon