It's not that the beans are hard, they contain enough oil that a blender (many times stronger than a blade coffee grinder) likely to reduce them to a greasy dust. That's fine if you're making Turkish coffee but not for anything else.
The best way to grind them...wait? Where did they come from if you don't have a grinder? Are they Starbucks? Another coffeehouse chain? Your local indie? Most of the previous will grind your coffee beans for you if you you bring coffee they sell you back to their store.
In a pinch, I once went to my local grocery store where I'm a regular and they know me and asked to use their conical burr-grinder. They said yes I think mostly because they wanted to keep my business.
As for cheap grinder, try your local Goodwill-type store. They're the kind of thing people often buy, never use then donate to get out of their cabinet. I got my $400 burr grinder second-hand for about $15. (They have no idea what they have or what the quality is. I also bought a Shun Nigiri (vegetable cleaver) for $5. MSRP: $210) Then because who knows what the condition of the burrs is or what it was used for, I replaced the burrs for another $20 from the manufacturer.