Go through your results for flights to Blenheim in New Zealand with Netflights. The most popular airlines for this route are Emirates, Singapore Airlines & Air New Zealand, with Emirates claiming the top spot. Although Qatar Airways usually has the best prices, it's best to double check what's available for your travel dates.
If these flights are too expensive, try searching for a different time of year. So if your dates are flexible, consider looking at different times of year.
Blenheim receives 26 direct and indirect flights every week, but the cheapest airline is normally Qatar Airways. So, if the flights to Blenheim don't work for you, you could always try searching for flights to other airports in New Zealand.
For even more options, check what other airports you could fly to Blenheim from. You might be able to make a saving by going from a different airport or city.