Investment opinions/advice sought

I have the opportunity to invest part of my paycheque in General Universal Stores stock. Yesterday the stock was at £5.85 per share, and this morning it’s at £5.74 per share. We can purchase the stock at 15% below the fair market value of the stock.

The earnings for the GUS subsidiary that employs me are increasing, so that’s a good thing.

Opinions sought: Should I invest? I’m thinking maybe $80/month.

Oops. Maybe this should be in IMHO.