MAI Basic Four Inc is so keen to convince the world that it really is serious about its $970m bid for Prime Computer Inc that apart from saying that it has now spent $10m on the thing in various fees, it is prepared to consider seriously raising the offer from its present $20 a share – if the Natick minimaker will open its books to MAI first: it also insists that MAI is definitely not itself for sale, but the market remains thoroughly sceptical – Prime shares, at around $17.125, are still well shy of the bid tag.