The only point I'd make is know your stats for your own domains but also check other domains which have sold on the aftermarket and have been published as such. There appears to be a slow run on sales in general at the moment although the forecasts for the 4th quarter of this year showed some optimism. This however does not appear to have carried through on the main and reported sales in general on NP have slowed too which would be a useful indicator of the state of the market. Check similar names to your own i.e. if other 3L dotbiz have sold, how often and for how much.
If you can afford to wait and you have a good feeling for your names it may be worth the renewal of some if not all and wait out the storm.