Hi
Nicochau, welcome to the forums!
If you're gonna buy used, then I don't think you will get a better deal than buying TEKNO. They tend to hold up and wear less than most race grade brands, plus they offer a lifetime 50% warranty for any worn/broken parts you mail into them:
https://www.teknorc.com/warranty-repair/
TEKNO plastic is the most durable I've seen in the industry, chances are the arms will have wallowed out at the suspension arms pins, and/or those pins might bend over time. Kinda hard to tell without rebuilding the car to inspect. The most obvious signs of wear will happen on the out drives, normally the pins on the dog bones should be replaced periodically. I use the
Mugen Pin Replacement Tool myself. The cost for the tool pays for itself on the very first use. It's far more economical to replace the pins rather then buy a new set of shafts. I have a SCT410.1 that is 6+ years old and it still has all original shafts on it. The key is to replace the pins at the first hint of any flat spots forming on them. If you don't then those flat spots will cut into the out drives and wear them out. If you don't replace worn out drives, then you will snap the drive shafts. Everything has a cascading effect, for instance, if you ever blow out a bearing in a hub, then excessive heat will have formed and melted the plastic causing slop in the hub. If you don't replace the hub, and simply put a fresh bearing in it, then you will continue to blow out bearings repeatedly.
That said, I would plan to buy a full set of bearings anyway, do a fresh rebuild, and go through the old pile of bearings to see which are still good, clean the good ones and prep your bearings for the next rebuild to make rebuilds go more quickly.
TEKNO is hardly overkill, consider it an investment that will stand the test of time... if properly cared for. What I like about TEKNO is that they do a really good job of providing parts for legacy vehicles too, if they discontinue a part, then there's always a forward compatible option so you don't ever have to worry about getting stuck with a car without parts support no matter how old it is.
GRP's are pretty good tires for street racing, if you are serious about buying the car, then I will work on an asphalt setup for you if interested. I used to run GT8 and did a RC8Be conversion many years ago, and can help you come up with a competitive ride in no time. Another speed secret is to sauce your tires, you can buy over the counter stuff from Sticky Kicks, or make your own blend using an empty shock bottle, flush it out with automotive Chlorinated Brake Cleaner, then fill it half way with the same brake cleaner and fill the other half of the bottle with Liquid Wrench spray. Place a few drops of solution on the tire and rub it in with an old toothbrush, apply sauce about 10 minutes before each race and it will feel like velco on a prepped asphalt track
Here's my buggy conversion to give you an idea of what to expect:
