When considering the cost of DD i reasoned it through based of the following,
  1. Cost of the bike.Was going to change road bike which would of cost at least another£2000/£3000 on top of cost of current bike,and that money would depreciate away over next 2/3 years anyway. 
 Built race bike for under £1700.Its got to be worth that and for a while aswell
 Road bike is more than good enough.IF you want to go fast do it on track 
 2. Vans and transport are all saleable assets at end of season 
 3 Time.Iwork a 60 hour week.2 kids,wife.Think of all the DIY you can get out of know your a racer
  4.We are only here once.This is not a dress rehersal 
 5.I don,t think the bikes are slow.I was passing and leaving  all types of jap multi track bikes at a Brands trackday.Its the corner speed that counts 
 Hope this helps