Four parameters will help you to make a good choice:

1. quantity – how many prints do you need? offset will be more interesting for more than 500 copies
2. quality – offset printing gives the best results, but is best quality really needed for this kind of job?
3. budget – depends on quantity and choice of paper – digital printing will be cheaper for less than 300 copies
4. time – when does it need to be ready? – the printing process of offset takes longer than for digital printing

The only difficult category is the one of 300 to 500 copies. In this case the purpose of the printed materials needs to be questioned. What do you need it for and who is your public?