second hand tubes are very comon
so I guess a max of £250.00 will get you a worthwhile one.
A tubes swop is easy BUT make sure if you do it you know how to set up after that or it wont be long till you need another....
Im guessing it will go for more than £100.00 for those in the know.......
Just as a note....Bulbs grow in the ground, Lamps go in digital pj's and Tubes go in crt's
Best of luck.