Firstly, please do not repost your questions under a different thread - I saw it the first time, and have deleted the newer duplicate.
Details have yet to be finalised, so I can't make any promises, but currently the plan is for IBrowse 3 to initially be a free upgrade for those who have purchased a full 2.5 license (new or upgrade). Those who bought a discounted, limited 68K only 2.5 upgrade key will need to pay a small fee to upgrade to IBrowse 3 (similar rate to the current 2.5 sidegrade price). It probably goes without saying that IBrowse 3.0 will not be exactly what was planned 20 years ago, but development is set to move from IBrowse 2.5 to IBrowse 3 sometime next year.