The most important factor is "feel". Feel effects the speed of the meter.
It's not important how many dots of feel it has but it's its important when you have made a choice to stick with balls with the same amount of feel. It may take a while but you will get used to the meter speed. Chopping and changing between balls with a different amount of feel will generally not help at all. When you change clubs you will (probably) notice a change in meter speed but like I say consistency is the key.
Picking a ball with 2 or 2.5 feel is probably the best choice as you can find both very cheap and more expensive balls with that amount of feel.
The best value balls are:
Srixon Z-STAR Balls (L11+) - 180 Credits
Srixon Z-STAR XV Balls (L13+) - 200 Credits
or
Callaway Tour i(s) Balls (L33+) - 250 credits
In terms of what you get they are all excellent value - you get some distance, some spin and feel. They are also highly durable and will last a good long time - about 3 full rounds per ball unless you lose them.