Not an expert but my kid used to love them, until he turned to the transformers universe (yesssssssss)
Takara is obviously the more expensive version than the hasbro one because of colour schemes that are toon accurate (the usual when comparing hasbro to takara)
Beyblades like any "collectable type" toys have commons, rares and ultra rares.
Beyblade burst and beyblade burst evolution is the newest version of beyblades and are the ones the kids want today because of what's playing on netflix and cable tv.
In terms of what to buy, depends on what your kid likes as each beyblade has their own characteristics. More defensive and less offensive, or vice versa. A good started pack would look something like this as it comes with the beyblade and a launcher.
https://www.walmart.ca/en/ip/beyblad.../6000197590174
- Stadiums where beyblades battle for sure is a must if you don't want dents and scuffs on your hardwood flooring.
https://www.walmart.ca/en/ip/beyblad.../6000197591146
After all this... it becomes more expensive than collecting Transformers.