@MadGyver It's good to hear genuine Yamaha parts are reasonably priced in Greece but they can be very expensive here in the UK. The relay arm bearings for example are about £35 each meaning you can have ten from Marksman Industrial for the price of two from Fowlers, and just keep changing them. And they're exactly the same part, just an engineering consumable of Japanese manufacture. Same story with the bushes from Simply Bearings, in fact if you look at the link these are available in widths up to 25mm which give more load-bearing area than the Yamaha items.
The seals from Simply Bearings are also better as they're double lipped with a garter spring (the genuine seals only have a single lip and are much more expensive). This means you can do the seal mod where you flip the seals so the garter spring faces outwards away from the bearing; the lip without the spring is just a dust wiper so you can then cut small sections out of this with Swiss Army Knife scissors (best/sharpest scissors I've ever used) or one of those leather punches so when you re-lube the linkage bearings with a grease gun, the hydraulic pressure is less likely to force the seals out. The grease is free to pass through the gaps in the dust seal lip (now on the inside) and lift up the lip with the garter spring as it moves through the bearing. The sprung lip then retracts, retaining enough grease inside the bearing and keeping dirt out.
If like me you're ham-fisted with the grease gun, it will still try and force out the seals so you can also hacksaw a section out of an M20 washer to make it U-shaped and insert it in the gap between the tiebars and the arm during greasing to prevent this (with the linkage bolted together and the seals where they should be, you can actually move the tiebar/sleeve assembly 2-3mm side to side; useful after you've greased up everything as with the bike on a MX bike stand, you can move it fully each way with light taps from a rubber mallet to make it splodge the excess grease away from the bearings/seals, then clean it all off thoroughly to prevent any getting on the rear tyre).
The cost of living is very high in the UK and the overcharging by some companies is just unreasonable, meaning many people end up adopting a state of mind where they are prepared to go out of their way to avoid giving that particular company or industry any money.
Here is an example; I've developed an interest in restoring mid-2000s mountain bikes because I don't want to buy a new one, and I happen to like 26" wheels and 3x9 transmissions (fun fact: a modern 29" wheel bike with 1x11 transmission gives up 10% climbing ability and 10% top speed compared to my bikes). So this week I found a 2006 S-Works Stumpjumper which has rear suspension which automatically switches between lockout and open. I have some Fox 32 forks which have the same feature, but you can't get parts for them any more because the UK MTB industry is trying to force me to buy a new bike/forks etc. The base valve in the damper has an adjustable blowoff valve with several O-rings I would like to replace whilst servicing the forks, but I don't have the special tool to get this apart and it had been Loctited by the previous owner. After 3 days of thinking it over, I finally managed this last night by gently heating it, then using a strap wrench with a small section of #1500 wet and dry to grip the cylindrical housing without damaging it (it's the thickness of an egg shell). So now I can fully service my 2007 Fox forks, and when they're fitted to this bike I'll be able to tune exactly when both ends change from locked out to open and make the forks and shock match each other, my riding style, weight, favourite trails etc.
Again I'm pleased for you that Yamaha parts are priced fairly where you live but it's not the case here in the UK so you have to wait until it starts raining (as it most assuredly will), go into the shed and get inventive. Just have to measure up the O-rings now which is usually the most difficult part! Cheers bud