Mods, is it ok for me to run a competition here? 3 prizes, £10 entry?

Prizes(if I can get 140 people):

• 1 year of lessons (44x1hr)
• 3 months (12x1hr)
• 1 month (4x1hr)

Is this against the rules?

I’d love to give back to this community but I can’t really afford to just give away lessons. I’d love someone who can’t afford a years lessons, to get a years lessons basically.