I do think that good developers and technical staff are harder to replace. You don't need exceptional specific knowledge to do sales. There are so many fields where within 6 months I have had to become almost expert across the board in a topic I had never previously visited, in a way that none of the clients I develop for have to be - admittedly without depth in some important areas.

However that is not to say I think good sales is 'less' worthwhile - it's generally an essential part of any business with a large effect on viability and profitability. Good salesmen are brilliant to work with and will smooth the paths we need to tread as technical guys. I wouldn't care to do it - I'm uncomfortable when stuck in a room of strangers to network, and all the other things that need doing. Phone calling saps my energy in a way that creative development does not.

I think as long as top performers could aspire to a similar level of pay in either sphere I would be happy. In my prior experience to my current job, salespeople always got better renumeration - here we don't really have any!