You're probably right about bikes being more relatively expensive now. According to the Bank of Canada's inflation calculator, a $300 basket of goods in 1983 would have only cost you $679 today.

However, back in 1986 a friend of mine bought a 105-equipped steel Norco for $635. In today's dollars (CAD) that would work out to be $1260, which is not too far off. You can get a 105-equipped alu bike for that much.

In today's market there are way more option than 30 years ago, and the differentiation in the market is partly responsible for the increase in prices.

Perhaps it's more relevant to talk about the affordability index of bikes, that is, wage vs. price, rather than in absolute cost.