We propose a new method to estimate changing task prices and skill accumulation across multiple sectors. The method exploits workers' wage growth in panel data, allowing for an arbitrary multidimensional distribution of skills, and endogenous switching due to price changes or skill shocks. We apply our method to German administrative records and find that the price for work in middle wage occupations declined considerably relative to the price of both high and low wage professions. We empirically identify that substantial selection effects afflict rising and benefit shrinking sectors: entrants as well as leavers to any sector earn less than stayers and rising (shrinking) sectors feature positive (negative) net entry. This has held back average wages in price increasing professions and it even overturned the rising task prices in the service sector. We find evidence that part of the large selection effect in services is due to deteriorating relative skills of entrants over time whereas the largest part of the selection effect in white-collar work is due to stayers' skill accumulation over the life cycle.