I don't really want to go through the expense of trademarking it (£250 starting price in UK) and on a seperate note I find what Groupon did very unethical (alth

I don't really want to go through the expense of trademarking it (£250 starting price in UK) and on a seperate note I find what Groupon did very unethical (although the guy got a really nice payout). I'm more interested (if anyone knows) whether I should be sending these guys an email pointing out that I already operate a website in the same space with the same name and whether prior use (without a trademark) counts for anything. They haven't launched yet, and I don't want to find in two years time that I cannot use my domain.