The similarity in laws between the ROI, NI and the UK is considerable as they all share the Common Law system. The Common Law system of law was developed from the English Common Law system and is predominant in most English speaking countries.
There may be some reform reflecting jurisdictions' requirements in recent years but the similarities outweighs differences.
If you are a potential Paralegal trying to decide which of the 3 jurisdiction systems to pursue, there is not a great deal of difference.
According to PayScale, the average base salary for a Paralegal in the Republic of Ireland is currently between €23,000 - €42,000 per year. An entry-level Paralegal with less than 1 year experience can expect to earn an average total compensation (includes tips, bonus, and overtime pay) of €25,490 based on 11 salaries. An early career Paralegal with 1-4 years of experience earns an average total compensation of €29,194 based on 29 salaries. An experienced Paralegal with 10-19 years of experience earns an average total compensation of €40,872 based on 7 salaries.