Hi DJfactory, and welcome to the forum by the way
I can recall (vaguely) when I first started learning to DJ; in the first few years, I would have considered and bought anything which I thought would help me to become "better", including electronic BPM counters, to help me overcome the "mysteries" of BPM's and beatmixing in general.
However, no-one
needs a BPM counter, certainly not when its only £40 (ish) less than the price of a mixer which has two BPM counters built in (EG: The Behringer VMX-300), which not only tells you the BPM's but also has graphic displays telling you which channel (music source) is running faster (or slower) than the other source.
But, taking a little extra time to practice "manual" beatmixing, will give you three distinct advantages.
1) £99 more in your pocket.
2) Ability to beatmix on any equipment, with or without a BPM counter.
3) Greater confidence and less prone to peer pressure eg: Your mates saying "Nice mix yeah, but now try it withou' yer beat counta!".
How is your beatmixing? if you're having particular issues then ask away, I'm sure that the rest of the forum will have various hints, tips and stories of how they overcame/got around similar concerns.