Don't really understand what you mean by "25btc plus".No keywords aren't that expensive.Microsoft/all other major websites have good google rankings because they're obviously better or they don't have any competitions.I have a list of keywords of trade and exchanges but certainly not selling them for more than $20 but I guess this not exactly what you will be looking for.
The ones that people already own those are the prices they are putting some bids are already up to 0.3 on some keywords. All the best keywords are taken, so if we want them we going to have to pay more for them.
Part of the prices already being put up
https://searchtrade.com/keywords/views/highestAsk.php you don't have to buy at that price i know you can put bids up an if they like them they can take your offer.