Interesting......
https://www.trainerroad.com/blog/the-cost-of-getting-faster/
But anyway my skinsuits/socks/etc all cheap cheap china cheong stuff lah, they work ok as long as not ngeow about materials and small nuances like very specific fit @ certain areas of the body. Hobbyist play play for fun grade still ok.
Past few weeks esp i have had quite a few experiences and i do think in real practical experiences, training is really key for cycling, assuming that you are still not @ top tier fitness. If you are near your peak potential, then yes the gains would be significantly smaller and harder to come by. Same goes for running.
Race environment would be different, but i think if you are cash strapped/dont wanna spend much, this is key.
Really dont relish spending 10-15k on bikes with electronic shifting and all that stuff, even 4-5k also not that interested.
Another thing is maintenance and stuff.....the only thing i can do is adjusting the hydraulic brake calipers so as to prevent rubbing and also cleaning drivetrain. If i keep on foldie platform, my "LBS" is just 2km away, and his charges are cheap, i have done 3 small and simple adjustments before and he did not even charge me a single cent. Other stuff are very cheap also. Labour dont say, confirm cheap, but even branded stuff (eg Schwalbe One tyres) are like even cheaper than half the price of shops/shopee. Another LBS which can do road bikes (Hup Leong @ Chin Swee), wow man..... at the rate i am going i think also not cheap in total.