Rule of thumbs in that class could be somewhere around £100 per flight hour fixed costs plus £100 per hour variable costs at 150 flight hours per years or £30,000 totals per year at half-half. The £15,000 fixed you have almost anyways, one way or another, flying only 50 hours per year would be £5,000 variable and totals £20,000 at only 50 flight hours, or £400 per hour. I would treat that as "Don't" while the £200 at 150 hours would be my "Do".
The biggest issues will be the birds shape upon acquisition and on the same level, the blindness of your buddies. Most such groups fail on reality view of its members - No you don't need no stinky golden blinkyblinky ...