Lawyers should not ask you for money in advance - these are the ripofers! The lawer takes about a 3rd of the payed liquidation as fee (unfortunately it is like that), so if your employer offers you something like 70 % of the total liquidation - take it! I do not know where you are located but a good lawyer works for results only in Liquidations! You would have to bring the calculations from the secretaria de los trabajadores and probably the name of the inspector you been with at your employers meeting! - Good luck!