If your wife puts in €600.
Her employer will put in €600
Total €1,200
5% contribution charge is €60
Net contribution: €1,140
She gets 20% tax relief on it, if I understand the taxation of married couples correctly. So that is €120 tax back.
So the net cost is €480.
It will grow tax-free.
Depending on her income in retirement, she could get it back tax-free.
Well worth it.
If her employer offers to pay her the €600 as gross salary, she might be better off taking that.
Brendan