In the mid 70s you could buy most Bordeaux reds at under US $10, and
even the first growths often could be had in the $20 - 30 range. Even
Romanee-Conti often cost well under $100, if you could find it. Many
very good Rhones were nearly given away. Now the 2000 first growths are
going for several hundred dollars. The 1985 Romanee-Conti sells at
auction for several thousand dollars. The best Rhones also can be quite
expensive. The Rhone growers should erect a huge statue to honor Robert
Parker for making their wines so much more respected and expensive. The
cost of the more desired high end wines has increased much more rapidly
than inflation since the 70s. Also the spread in prices between a decent
classified Bordeaux and a first growth has increased. Also there has
been a huge increase in the price of many US and Australian wines of the
cult sort, and a decent, but not cult, California Cabernet Sauvignon is
now not inexpensive.

The bottom price now probably is in the US$ 2-3 range per 750 ml for 5L
box wines. Many of these do not have serious technical flaws as did many
cheap wines in the past, but then they seldom have anything exciting
either. The upper limit for new releases has moved up to over $US 1000.
for some very famous and cult wines in the more desired years.

Rating wines as cheap to expensive depends on your income, and how
freely you spend money. To a very rich person who collects old masters,
even the cost of Romanee-Conti may not seem very high. For the poor,
even a US$ 5 bottle of wine may seem expensive.