Which is better and why? Is there much difference between the 2?
Is the price justified for these, seems expensive at around £65 per month?
Do you still need a subscription with these after you have found and ordered your product (homework period)?
Back in 2018, I started out with Jungle Scout but when I actually started selling I switched to H10 as it had a much more complete suite of tools. I haven't used JS for a few years so they may have caught up.
£65 is a lot of money in the early days, it would certainly be reasonable to only sign up during the product research stage and then cancel the subscription until you need it again e.g. when you get to the keyword research stage, listing optimisation, rank tracking, listing monitoring etc.
For me, it is essential at the product research stage and at the product launch stage (and ongoing after that).
I use Jungle Scout as I find it works well and quite accurate and is less expensive than H10. The only tool I use is the chrome extension, the other tools I find superfluous to what I need to do. I just buy it when needed, not on an ongoing basis.