Talking about old Yamahas here:
A motor rebuild typically costs me ~$400 for piston kit, rebore, bearings, seals, paint and other fiddly crap. Add ~$200 if it needs a rod kit.
I've never owned anything rare enough to have to fork out for new gears etc - I just buy another ratty motor for $50 and get the bits that way.
Labour is all my own.
Chain and sprockets are ~$200 for decent stuff.
Tyres are ~$200/pair.
Basic reseal on a rear (single) shock is $180 or so (or $60 for parts/oil if you can DIY).
Levers, grips, bars, etc are about $200 for the lot.
Fork reseal is about $50 in parts/oil. Add $200ish for rechroming and ~$100 for rebushing if needed.
Seat covers are typically $50.
Air filter is ~$50.
A set of plastics is usually around $250
if you can get them.
Professional painting is mega-bucks. I am happy enough to do it myself for about $100 worth of materials - the finish is acceptable, but the pro job will stay looking good for a lot longer.
Wheel bearings are usually around $50 for the whole lot.
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That's the stuff that I consider to be inevitable to get the bike to a decent race standard. Usually, you'll be able to use some of the bits that come on the bike without spending money, but it depends on how pretty/fast you want it to be.
There will always be some other stuff that is needed - fuel tank resto ($500 for an alloy tank), fork boots ($40), brake shoes ($50), cables ($100), rear suspension linkage bits ($250ish), or you might discover that the barrel is on the last over-size, etc etc.
Upgrade stuff also shoots the price up - stuff like PD valves and good shocks and good pipes can easily add another $2k to the cost of a rebuild.
And dont forget that some bikes have expensive bits that an add up really quicly - YZ-G/H sidecovers, for example...
I always cringe when Ted talks money, but then I look at his bikes and they're a LOT nicer than mine...