One of the advantages of my stock deals is that they provide a way to "tip" reliable tech buyers and sellers.
See
http://forums.cybernations.net/index.php?showtopic=65480I find the $3 million for 100 tech standard price a bit tiresome, even though that is mostly what people are doing. The profitability limit on tech levels is a big constraint, and if you had enough nations get past 100 tech long term, the market would simply dry up. Bottom line - fixed rates in the tech market really make no sense at all. There should be more price competition as well as risk assessment.
Personally, I prefer smaller arrangements that can be concluded in 20 days, but in a longer relationship you can offer other incentives. The main thing, from the sellers end, is to keep enough cash out and secure so you can service all your deals in a timely manner and not get caught in a liquidity squeeze. I'm using a spreadsheet to project my income and payouts forward and make sure there is enough money in the till.
WF