Hi Ronaldo
It's unlikely that you need to invest in 10 shares immediately or at all.
This would be a requirement for a retired person with no other source of income who would need that level of diversification.
If you buy 3 shares, the portfolio might not be diversified, but if you own your own home, it will only be a small percentage of your total wealth.
I would buy in units of €5,000.
After the charges of buying and selling the shares, the annual exemption is just not worth availing of. If you were selling shares anyway coming up to the end of the year, you might sell some before the end of the year and some after to avail of both years' exemptions.
Brendan