Ah,hairylemon,it would appear you have no idea the costs involved in building(if you have the knowledge)or having built a A15 able to generate even close to 136 r/w h.p.

Even at mates rates a knowlegable spanner will cost you $500 per day and he will spend at least 2 days working an engine up.
Then we have the host of machining that is involved and the costs associated,if you don't believe me try ringing around and asking a few questions on machining costs,pushing pistons on and off rods etc. etc.
We are yet to buy all the internal bits yet,new pistons,and they won't be the poxey deep dish A15 standard jobbies.Rings,big end and main bearings over sized to match the machined crank journals,seals,gaskets,a purpose built Wilkins head gasket at about $150.00 and we hav'nt even thought about buying a base head and spending another grand or so on it,remember where looking for over 120HP at the treads.
Few casual observers have any idea of the costs involved in building engines and components for use in competition and i would rarely comment on someones inexperianced comments,but on this occasion i would think that $4000.00 in reciepts is easily achievable and worth every cent given the dyno figures.
You do the maths.
Cheers
Bert