A lot podcasts I listen to have adds for companies selling roses for Valentine's day. The host often commnets how much cheaper roses have gotten over the years. I tried and tried but can't find historical prices for a dozen roses, but my guess is that roses prices have fallen in real terms (adjusting for inflation) because of imports from Colombia and Ecuador. The Hertiage Foundation reports that Americans saved 16million dollars last year from reduced tariffs on Colombian roses.
Of course some are worried about labor conditions in other countries, so now you can even get Fair Trade roses.
If anyone has data on historical rose prices I would be curious.