Actually, as one of the owners of the Staverton, Gloucestershire, Tiger Airways Biplane outfit; yes it is that expensive to maintain old biplanes. Engine TBO 850 hours (they usually don't make it), overhaul cost around £30,000. Generally about five hours of engineers time for each hour the aircraft flies. But they are fun to fly. Gift Experience companies generally operate on mark-ups of around 20 - 60% on the slightly discounted prices we give them, buying direct from the operator is almost always better value.