Honestly mate, if you are just starting out with carts a battery is a battery. Some cart sellers on here have batteries for sale for a few quid of if you really want to spend a bit more then get a CCell Silo or similar on Amazon.
If you get hooked on carts (not in itself a good idea) then you can spend a bit more for cool looking gear, pre-heat and variable voltages and other gimmicks but honestly it is still just a battery...
If you get hooked on carts (not in itself a good idea) then you can spend a bit more for cool looking gear, pre-heat and variable voltages and other gimmicks but honestly it is still just a battery...